perldiag(1)


NAME

   perldiag - various Perl diagnostics

DESCRIPTION

   These messages are classified as follows (listed in increasing order of
   desperation):

       (W) A warning (optional).
       (D) A deprecation (enabled by default).
       (S) A severe warning (enabled by default).
       (F) A fatal error (trappable).
       (P) An internal error you should never see (trappable).
       (X) A very fatal error (nontrappable).
       (A) An alien error message (not generated by Perl).

   The majority of messages from the first three classifications above (W,
   D & S) can be controlled using the "warnings" pragma.

   If a message can be controlled by the "warnings" pragma, its warning
   category is included with the classification letter in the description
   below.  E.g. "(W closed)" means a warning in the "closed" category.

   Optional warnings are enabled by using the "warnings" pragma or the -w
   and -W switches.  Warnings may be captured by setting $SIG{__WARN__} to
   a reference to a routine that will be called on each warning instead of
   printing it.  See perlvar.

   Severe warnings are always enabled, unless they are explicitly disabled
   with the "warnings" pragma or the -X switch.

   Trappable errors may be trapped using the eval operator.  See "eval" in
   perlfunc.  In almost all cases, warnings may be selectively disabled or
   promoted to fatal errors using the "warnings" pragma.  See warnings.

   The messages are in alphabetical order, without regard to upper or
   lower-case.  Some of these messages are generic.  Spots that vary are
   denoted with a %s or other printf-style escape.  These escapes are
   ignored by the alphabetical order, as are all characters other than
   letters.  To look up your message, just ignore anything that is not a
   letter.

   accept() on closed socket %s
       (W closed) You tried to do an accept on a closed socket.  Did you
       forget to check the return value of your socket() call?  See
       "accept" in perlfunc.

   Aliasing via reference is experimental
       (S experimental::refaliasing) This warning is emitted if you use a
       reference constructor on the left-hand side of an assignment to
       alias one variable to another.  Simply suppress the warning if you
       want to use the feature, but know that in doing so you are taking
       the risk of using an experimental feature which may change or be
       removed in a future Perl version:

           no warnings "experimental::refaliasing";
           use feature "refaliasing";
           \$x = \$y;

   Allocation too large: %x
       (X) You can't allocate more than 64K on an MS-DOS machine.

   '%c' allowed only after types %s in %s
       (F) The modifiers '!', '<' and '>' are allowed in pack() or
       unpack() only after certain types.  See "pack" in perlfunc.

   alpha->numify() is lossy
       (W numeric) An alpha version can not be numified without losing
       information.

   Ambiguous call resolved as CORE::%s(), qualify as such or use &
       (W ambiguous) A subroutine you have declared has the same name as a
       Perl keyword, and you have used the name without qualification for
       calling one or the other.  Perl decided to call the builtin because
       the subroutine is not imported.

       To force interpretation as a subroutine call, either put an
       ampersand before the subroutine name, or qualify the name with its
       package.  Alternatively, you can import the subroutine (or pretend
       that it's imported with the "use subs" pragma).

       To silently interpret it as the Perl operator, use the "CORE::"
       prefix on the operator (e.g. "CORE::log($x)") or declare the
       subroutine to be an object method (see "Subroutine Attributes" in
       perlsub or attributes).

   Ambiguous range in transliteration operator
       (F) You wrote something like "tr/a-z-0//" which doesn't mean
       anything at all.  To include a "-" character in a transliteration,
       put it either first or last.  (In the past, "tr/a-z-0//" was
       synonymous with "tr/a-y//", which was probably not what you would
       have expected.)

   Ambiguous use of %s resolved as %s
       (S ambiguous) You said something that may not be interpreted the
       way you thought.  Normally it's pretty easy to disambiguate it by
       supplying a missing quote, operator, parenthesis pair or
       declaration.

   Ambiguous use of -%s resolved as -&%s()
       (S ambiguous) You wrote something like "-foo", which might be the
       string "-foo", or a call to the function "foo", negated.  If you
       meant the string, just write "-foo".  If you meant the function
       call, write "-foo()".

   Ambiguous use of %c resolved as operator %c
       (S ambiguous) "%", "&", and "*" are both infix operators (modulus,
       bitwise and, and multiplication) and initial special characters
       (denoting hashes, subroutines and typeglobs), and you said
       something like "*foo * foo" that might be interpreted as either of
       them.  We assumed you meant the infix operator, but please try to
       make it more clear -- in the example given, you might write "*foo *
       foo()" if you really meant to multiply a glob by the result of
       calling a function.

   Ambiguous use of %c{%s} resolved to %c%s
       (W ambiguous) You wrote something like "@{foo}", which might be
       asking for the variable @foo, or it might be calling a function
       named foo, and dereferencing it as an array reference.  If you
       wanted the variable, you can just write @foo.  If you wanted to
       call the function, write "@{foo()}" ... or you could just not have
       a variable and a function with the same name, and save yourself a
       lot of trouble.

   Ambiguous use of %c{%s[...]} resolved to %c%s[...]
   Ambiguous use of %c{%s{...}} resolved to %c%s{...}
       (W ambiguous) You wrote something like "${foo[2]}" (where foo
       represents the name of a Perl keyword), which might be looking for
       element number 2 of the array named @foo, in which case please
       write $foo[2], or you might have meant to pass an anonymous
       arrayref to the function named foo, and then do a scalar deref on
       the value it returns.  If you meant that, write "${foo([2])}".

       In regular expressions, the "${foo[2]}" syntax is sometimes
       necessary to disambiguate between array subscripts and character
       classes.  "/$length[2345]/", for instance, will be interpreted as
       $length followed by the character class "[2345]".  If an array
       subscript is what you want, you can avoid the warning by changing
       "/${length[2345]}/" to the unsightly "/${\$length[2345]}/", by
       renaming your array to something that does not coincide with a
       built-in keyword, or by simply turning off warnings with "no
       warnings 'ambiguous';".

   '|' and '<' may not both be specified on command line
       (F) An error peculiar to VMS.  Perl does its own command line
       redirection, and found that STDIN was a pipe, and that you also
       tried to redirect STDIN using '<'.  Only one STDIN stream to a
       customer, please.

   '|' and '>' may not both be specified on command line
       (F) An error peculiar to VMS.  Perl does its own command line
       redirection, and thinks you tried to redirect stdout both to a file
       and into a pipe to another command.  You need to choose one or the
       other, though nothing's stopping you from piping into a program or
       Perl script which 'splits' output into two streams, such as

           open(OUT,">$ARGV[0]") or die "Can't write to $ARGV[0]: $!";
           while (<STDIN>) {
               print;
               print OUT;
           }
           close OUT;

   Applying %s to %s will act on scalar(%s)
       (W misc) The pattern match ("//"), substitution ("s///"), and
       transliteration ("tr///") operators work on scalar values.  If you
       apply one of them to an array or a hash, it will convert the array
       or hash to a scalar value (the length of an array, or the
       population info of a hash) and then work on that scalar value.
       This is probably not what you meant to do.  See "grep" in perlfunc
       and "map" in perlfunc for alternatives.

   Arg too short for msgsnd
       (F) msgsnd() requires a string at least as long as sizeof(long).

   Argument "%s" isn't numeric%s
       (W numeric) The indicated string was fed as an argument to an
       operator that expected a numeric value instead.  If you're
       fortunate the message will identify which operator was so
       unfortunate.

       Note that for the "Inf" and "NaN" (infinity and not-a-number) the
       definition of "numeric" is somewhat unusual: the strings themselves
       (like "Inf") are considered numeric, and anything following them is
       considered non-numeric.

   Argument list not closed for PerlIO layer "%s"
       (W layer) When pushing a layer with arguments onto the Perl I/O
       system you forgot the ) that closes the argument list.  (Layers
       take care of transforming data between external and internal
       representations.)  Perl stopped parsing the layer list at this
       point and did not attempt to push this layer.  If your program
       didn't explicitly request the failing operation, it may be the
       result of the value of the environment variable PERLIO.

   Argument "%s" treated as 0 in increment (++)
       (W numeric) The indicated string was fed as an argument to the "++"
       operator which expects either a number or a string matching
       "/^[a-zA-Z]*[0-9]*\z/".  See "Auto-increment and Auto-decrement" in
       perlop for details.

   Array passed to stat will be coerced to a scalar%s
       (W syntax) You called stat() on an array, but the array will be
       coerced to a scalar - the number of elements in the array.

   assertion botched: %s
       (X) The malloc package that comes with Perl had an internal
       failure.

   Assertion %s failed: file "%s", line %d
       (X) A general assertion failed.  The file in question must be
       examined.

   Assigned value is not a reference
       (F) You tried to assign something that was not a reference to an
       lvalue reference (e.g., "\$x = $y").  If you meant to make $x an
       alias to $y, use "\$x = \$y".

   Assigned value is not %s reference
       (F) You tried to assign a reference to a reference constructor, but
       the two references were not of the same type.  You cannot alias a
       scalar to an array, or an array to a hash; the two types must
       match.

           \$x = \@y;  # error
           \@x = \%y;  # error
            $y = [];
           \$x = $y;   # error; did you mean \$y?

   Assigning non-zero to $[ is no longer possible
       (F) When the "array_base" feature is disabled (e.g., under "use
       v5.16;") the special variable $[, which is deprecated, is now a
       fixed zero value.

   Assignment to both a list and a scalar
       (F) If you assign to a conditional operator, the 2nd and 3rd
       arguments must either both be scalars or both be lists.  Otherwise
       Perl won't know which context to supply to the right side.

   Assuming NOT a POSIX class since %s in regex; marked by <--HERE in
   m/%s/
       (W regexp) You had something like these:

        [[:alnum]]
        [[:digit:xyz]

       They look like they might have been meant to be the POSIX classes
       "[:alnum:]" or "[:digit:]".  If so, they should be written:

        [[:alnum:]]
        [[:digit:]xyz]

       Since these aren't legal POSIX class specifications, but are legal
       bracketed character classes, Perl treats them as the latter.  In
       the first example, it matches the characters ":", "[", "a", "l",
       "m", "n", and "u".

       If these weren't meant to be POSIX classes, this warning message is
       spurious, and can be suppressed by reordering things, such as

        [[al:num]]

       or

        [[:munla]]

   <> at require-statement should be quotes
       (F) You wrote "require <file>" when you should have written
       "require 'file'".

   Attempt to access disallowed key '%s' in a restricted hash
       (F) The failing code has attempted to get or set a key which is not
       in the current set of allowed keys of a restricted hash.

   Attempt to bless into a freed package
       (F) You wrote "bless $foo" with one argument after somehow causing
       the current package to be freed.  Perl cannot figure out what to
       do, so it throws up in hands in despair.

   Attempt to bless into a reference
       (F) The CLASSNAME argument to the bless() operator is expected to
       be the name of the package to bless the resulting object into.
       You've supplied instead a reference to something: perhaps you wrote

           bless $self, $proto;

       when you intended

           bless $self, ref($proto) || $proto;

       If you actually want to bless into the stringified version of the
       reference supplied, you need to stringify it yourself, for example
       by:

           bless $self, "$proto";

   Attempt to clear deleted array
       (S debugging) An array was assigned to when it was being freed.
       Freed values are not supposed to be visible to Perl code.  This can
       also happen if XS code calls "av_clear" from a custom magic
       callback on the array.

   Attempt to delete disallowed key '%s' from a restricted hash
       (F) The failing code attempted to delete from a restricted hash a
       key which is not in its key set.

   Attempt to delete readonly key '%s' from a restricted hash
       (F) The failing code attempted to delete a key whose value has been
       declared readonly from a restricted hash.

   Attempt to free non-arena SV: 0x%x
       (S internal) All SV objects are supposed to be allocated from
       arenas that will be garbage collected on exit.  An SV was
       discovered to be outside any of those arenas.

   Attempt to free nonexistent shared string '%s'%s
       (S internal) Perl maintains a reference-counted internal table of
       strings to optimize the storage and access of hash keys and other
       strings.  This indicates someone tried to decrement the reference
       count of a string that can no longer be found in the table.

   Attempt to free temp prematurely: SV 0x%x
       (S debugging) Mortalized values are supposed to be freed by the
       free_tmps() routine.  This indicates that something else is freeing
       the SV before the free_tmps() routine gets a chance, which means
       that the free_tmps() routine will be freeing an unreferenced scalar
       when it does try to free it.

   Attempt to free unreferenced glob pointers
       (S internal) The reference counts got screwed up on symbol aliases.

   Attempt to free unreferenced scalar: SV 0x%x
       (S internal) Perl went to decrement the reference count of a scalar
       to see if it would go to 0, and discovered that it had already gone
       to 0 earlier, and should have been freed, and in fact, probably was
       freed.  This could indicate that SvREFCNT_dec() was called too many
       times, or that SvREFCNT_inc() was called too few times, or that the
       SV was mortalized when it shouldn't have been, or that memory has
       been corrupted.

   Attempt to pack pointer to temporary value
       (W pack) You tried to pass a temporary value (like the result of a
       function, or a computed expression) to the "p" pack() template.
       This means the result contains a pointer to a location that could
       become invalid anytime, even before the end of the current
       statement.  Use literals or global values as arguments to the "p"
       pack() template to avoid this warning.

   Attempt to reload %s aborted.
       (F) You tried to load a file with "use" or "require" that failed to
       compile once already.  Perl will not try to compile this file again
       unless you delete its entry from %INC.  See "require" in perlfunc
       and "%INC" in perlvar.

   Attempt to set length of freed array
       (W misc) You tried to set the length of an array which has been
       freed.  You can do this by storing a reference to the scalar
       representing the last index of an array and later assigning through
       that reference.  For example

           $r = do {my @a; \$#a};
           $$r = 503

   Attempt to use reference as lvalue in substr
       (W substr) You supplied a reference as the first argument to
       substr() used as an lvalue, which is pretty strange.  Perhaps you
       forgot to dereference it first.  See "substr" in perlfunc.

   Attribute "locked" is deprecated
       (D deprecated) You have used the attributes pragma to modify the
       "locked" attribute on a code reference.  The :locked attribute is
       obsolete, has had no effect since 5005 threads were removed, and
       will be removed in a future release of Perl 5.

   Attribute prototype(%s) discards earlier prototype attribute in same
   sub
       (W misc) A sub was declared as sub foo : prototype(A) :
       prototype(B) {}, for example.  Since each sub can only have one
       prototype, the earlier declaration(s) are discarded while the last
       one is applied.

   Attribute "unique" is deprecated
       (D deprecated) You have used the attributes pragma to modify the
       "unique" attribute on an array, hash or scalar reference.  The
       :unique attribute has had no effect since Perl 5.8.8, and will be
       removed in a future release of Perl 5.

   av_reify called on tied array
       (S debugging) This indicates that something went wrong and Perl got
       very confused about @_ or @DB::args being tied.

   Bad arg length for %s, is %u, should be %d
       (F) You passed a buffer of the wrong size to one of msgctl(),
       semctl() or shmctl().  In C parlance, the correct sizes are,
       respectively, sizeof(structmsqid_ds*), sizeof(structsemid_ds*),
       and sizeof(structshmid_ds*).

   Bad evalled substitution pattern
       (F) You've used the "/e" switch to evaluate the replacement for a
       substitution, but perl found a syntax error in the code to
       evaluate, most likely an unexpected right brace '}'.

   Bad filehandle: %s
       (F) A symbol was passed to something wanting a filehandle, but the
       symbol has no filehandle associated with it.  Perhaps you didn't do
       an open(), or did it in another package.

   Bad free() ignored
       (S malloc) An internal routine called free() on something that had
       never been malloc()ed in the first place.  Mandatory, but can be
       disabled by setting environment variable "PERL_BADFREE" to 0.

       This message can be seen quite often with DB_File on systems with
       "hard" dynamic linking, like "AIX" and "OS/2".  It is a bug of
       "Berkeley DB" which is left unnoticed if "DB" uses forgiving system
       malloc().

   Bad hash
       (P) One of the internal hash routines was passed a null HV pointer.

   Badly placed ()'s
       (A) You've accidentally run your script through csh instead of
       Perl.  Check the #! line, or manually feed your script into Perl
       yourself.

   Bad name after %s
       (F) You started to name a symbol by using a package prefix, and
       then didn't finish the symbol.  In particular, you can't
       interpolate outside of quotes, so

           $var = 'myvar';
           $sym = mypack::$var;

       is not the same as

           $var = 'myvar';
           $sym = "mypack::$var";

   Bad plugin affecting keyword '%s'
       (F) An extension using the keyword plugin mechanism violated the
       plugin API.

   Bad realloc() ignored
       (S malloc) An internal routine called realloc() on something that
       had never been malloc()ed in the first place.  Mandatory, but can
       be disabled by setting the environment variable "PERL_BADFREE" to
       1.

   Bad symbol for array
       (P) An internal request asked to add an array entry to something
       that wasn't a symbol table entry.

   Bad symbol for dirhandle
       (P) An internal request asked to add a dirhandle entry to something
       that wasn't a symbol table entry.

   Bad symbol for filehandle
       (P) An internal request asked to add a filehandle entry to
       something that wasn't a symbol table entry.

   Bad symbol for hash
       (P) An internal request asked to add a hash entry to something that
       wasn't a symbol table entry.

   Bad symbol for scalar
       (P) An internal request asked to add a scalar entry to something
       that wasn't a symbol table entry.

   Bareword found in conditional
       (W bareword) The compiler found a bareword where it expected a
       conditional, which often indicates that an || or && was parsed as
       part of the last argument of the previous construct, for example:

           open FOO || die;

       It may also indicate a misspelled constant that has been
       interpreted as a bareword:

           use constant TYPO => 1;
           if (TYOP) { print "foo" }

       The "strict" pragma is useful in avoiding such errors.

   Bareword "%s" not allowed while "strict subs" in use
       (F) With "strict subs" in use, a bareword is only allowed as a
       subroutine identifier, in curly brackets or to the left of the "=>"
       symbol.  Perhaps you need to predeclare a subroutine?

   Bareword "%s" refers to nonexistent package
       (W bareword) You used a qualified bareword of the form "Foo::", but
       the compiler saw no other uses of that namespace before that point.
       Perhaps you need to predeclare a package?

   BEGIN failed--compilation aborted
       (F) An untrapped exception was raised while executing a BEGIN
       subroutine.  Compilation stops immediately and the interpreter is
       exited.

   BEGIN not safe after errors--compilation aborted
       (F) Perl found a "BEGIN {}" subroutine (or a "use" directive, which
       implies a "BEGIN {}") after one or more compilation errors had
       already occurred.  Since the intended environment for the "BEGIN
       {}" could not be guaranteed (due to the errors), and since
       subsequent code likely depends on its correct operation, Perl just
       gave up.

   \%d better written as $%d
       (W syntax) Outside of patterns, backreferences live on as
       variables.  The use of backslashes is grandfathered on the right-
       hand side of a substitution, but stylistically it's better to use
       the variable form because other Perl programmers will expect it,
       and it works better if there are more than 9 backreferences.

   Binary number > 0b11111111111111111111111111111111 non-portable
       (W portable) The binary number you specified is larger than 2**32-1
       (4294967295) and therefore non-portable between systems.  See
       perlport for more on portability concerns.

   bind() on closed socket %s
       (W closed) You tried to do a bind on a closed socket.  Did you
       forget to check the return value of your socket() call?  See "bind"
       in perlfunc.

   binmode() on closed filehandle %s
       (W unopened) You tried binmode() on a filehandle that was never
       opened.  Check your control flow and number of arguments.

   Bit vector size > 32 non-portable
       (W portable) Using bit vector sizes larger than 32 is non-portable.

   Bizarre copy of %s
       (P) Perl detected an attempt to copy an internal value that is not
       copiable.

   Bizarre SvTYPE [%d]
       (P) When starting a new thread or returning values from a thread,
       Perl encountered an invalid data type.

   Both or neither range ends should be Unicode in regex; marked by
   <--HERE in m/%s/
       (W regexp) (only under "usere'strict'" or within "(?[...])")

       In a bracketed character class in a regular expression pattern, you
       had a range which has exactly one end of it specified using "\N{}",
       and the other end is specified using a non-portable mechanism.
       Perl treats the range as a Unicode range, that is, all the
       characters in it are considered to be the Unicode characters, and
       which may be different code points on some platforms Perl runs on.
       For example, "[\N{U+06}-\x08]" is treated as if you had instead
       said "[\N{U+06}-\N{U+08}]", that is it matches the characters whose
       code points in Unicode are 6, 7, and 8.  But that "\x08" might
       indicate that you meant something different, so the warning gets
       raised.

   Buffer overflow in prime_env_iter: %s
       (W internal) A warning peculiar to VMS.  While Perl was preparing
       to iterate over %ENV, it encountered a logical name or symbol
       definition which was too long, so it was truncated to the string
       shown.

   Callback called exit
       (F) A subroutine invoked from an external package via call_sv()
       exited by calling exit.

   %s() called too early to check prototype
       (W prototype) You've called a function that has a prototype before
       the parser saw a definition or declaration for it, and Perl could
       not check that the call conforms to the prototype.  You need to
       either add an early prototype declaration for the subroutine in
       question, or move the subroutine definition ahead of the call to
       get proper prototype checking.  Alternatively, if you are certain
       that you're calling the function correctly, you may put an
       ampersand before the name to avoid the warning.  See perlsub.

   Calling POSIX::%s() is deprecated
       (D deprecated) You called a function whose use is deprecated.  See
       the function's name in POSIX for details.

   Cannot chr %f
       (F) You passed an invalid number (like an infinity or not-a-number)
       to "chr".

   Cannot compress %f in pack
       (F) You tried compressing an infinity or not-a-number as an
       unsigned integer with BER, which makes no sense.

   Cannot compress integer in pack
       (F) An argument to pack("w",...) was too large to compress.  The
       BER compressed integer format can only be used with positive
       integers, and you attempted to compress a very large number (>
       1e308).  See "pack" in perlfunc.

   Cannot compress negative numbers in pack
       (F) An argument to pack("w",...) was negative.  The BER compressed
       integer format can only be used with positive integers.  See "pack"
       in perlfunc.

   Cannot convert a reference to %s to typeglob
       (F) You manipulated Perl's symbol table directly, stored a
       reference in it, then tried to access that symbol via conventional
       Perl syntax.  The access triggers Perl to autovivify that typeglob,
       but it there is no legal conversion from that type of reference to
       a typeglob.

   Cannot copy to %s
       (P) Perl detected an attempt to copy a value to an internal type
       that cannot be directly assigned to.

   Cannot find encoding "%s"
       (S io) You tried to apply an encoding that did not exist to a
       filehandle, either with open() or binmode().

   Cannot pack %f with '%c'
       (F) You tried converting an infinity or not-a-number to an integer,
       which makes no sense.

   Cannot printf %f with '%c'
       (F) You tried printing an infinity or not-a-number as a character
       (%c), which makes no sense.  Maybe you meant '%s', or just
       stringifying it?

   Cannot set tied @DB::args
       (F) "caller" tried to set @DB::args, but found it tied.  Tying
       @DB::args is not supported.  (Before this error was added, it used
       to crash.)

   Cannot tie unreifiable array
       (P) You somehow managed to call "tie" on an array that does not
       keep a reference count on its arguments and cannot be made to do
       so.  Such arrays are not even supposed to be accessible to Perl
       code, but are only used internally.

   Cannot yet reorder sv_catpvfn() arguments from va_list
       (F) Some XS code tried to use "sv_catpvfn()" or a related function
       with a format string that specifies explicit indexes for some of
       the elements, and using a C-style variable-argument list (a
       "va_list"). This is not currently supported. XS authors wanting to
       do this must instead construct a C array of "SV*" scalars
       containing the arguments.

   Can only compress unsigned integers in pack
       (F) An argument to pack("w",...) was not an integer.  The BER
       compressed integer format can only be used with positive integers,
       and you attempted to compress something else.  See "pack" in
       perlfunc.

   Can't bless non-reference value
       (F) Only hard references may be blessed.  This is how Perl
       "enforces" encapsulation of objects.  See perlobj.

   Can't "break" in a loop topicalizer
       (F) You called "break", but you're in a "foreach" block rather than
       a "given" block.  You probably meant to use "next" or "last".

   Can't "break" outside a given block
       (F) You called "break", but you're not inside a "given" block.

   Can't call method "%s" on an undefined value
       (F) You used the syntax of a method call, but the slot filled by
       the object reference or package name contains an undefined value.
       Something like this will reproduce the error:

           $BADREF = undef;
           process $BADREF 1,2,3;
           $BADREF->process(1,2,3);

   Can't call method "%s" on unblessed reference
       (F) A method call must know in what package it's supposed to run.
       It ordinarily finds this out from the object reference you supply,
       but you didn't supply an object reference in this case.  A
       reference isn't an object reference until it has been blessed.  See
       perlobj.

   Can't call method "%s" without a package or object reference
       (F) You used the syntax of a method call, but the slot filled by
       the object reference or package name contains an expression that
       returns a defined value which is neither an object reference nor a
       package name.  Something like this will reproduce the error:

           $BADREF = 42;
           process $BADREF 1,2,3;
           $BADREF->process(1,2,3);

   Can't call mro_isa_changed_in() on anonymous symbol table
       (P) Perl got confused as to whether a hash was a plain hash or a
       symbol table hash when trying to update @ISA caches.

   Can't call mro_method_changed_in() on anonymous symbol table
       (F) An XS module tried to call "mro_method_changed_in" on a hash
       that was not attached to the symbol table.

   Can't chdir to %s
       (F) You called "perl -x/foo/bar", but /foo/bar is not a directory
       that you can chdir to, possibly because it doesn't exist.

   Can't check filesystem of script "%s" for nosuid
       (P) For some reason you can't check the filesystem of the script
       for nosuid.

   Can't coerce %s to %s in %s
       (F) Certain types of SVs, in particular real symbol table entries
       (typeglobs), can't be forced to stop being what they are.  So you
       can't say things like:

           *foo += 1;

       You CAN say

           $foo = *foo;
           $foo += 1;

       but then $foo no longer contains a glob.

   Can't "continue" outside a when block
       (F) You called "continue", but you're not inside a "when" or
       "default" block.

   Can't create pipe mailbox
       (P) An error peculiar to VMS.  The process is suffering from
       exhausted quotas or other plumbing problems.

   Can't declare %s in "%s"
       (F) Only scalar, array, and hash variables may be declared as "my",
       "our" or "state" variables.  They must have ordinary identifiers as
       names.

   Can't "default" outside a topicalizer
       (F) You have used a "default" block that is neither inside a
       "foreach" loop nor a "given" block.  (Note that this error is
       issued on exit from the "default" block, so you won't get the error
       if you use an explicit "continue".)

   Can't do inplace edit: %s is not a regular file
       (S inplace) You tried to use the -i switch on a special file, such
       as a file in /dev, a FIFO or an uneditable directory.  The file was
       ignored.

   Can't do inplace edit on %s: %s
       (S inplace) The creation of the new file failed for the indicated
       reason.

   Can't do inplace edit without backup
       (F) You're on a system such as MS-DOS that gets confused if you try
       reading from a deleted (but still opened) file.  You have to say
       "-i.bak", or some such.

   Can't do inplace edit: %s would not be unique
       (S inplace) Your filesystem does not support filenames longer than
       14 characters and Perl was unable to create a unique filename
       during inplace editing with the -i switch.  The file was ignored.

   Can't do %s("%s") on non-UTF-8 locale; resolved to "%s".
       (W locale) You are 1) running under ""use locale""; 2) the current
       locale is not a UTF-8 one; 3) you tried to do the designated case-
       change operation on the specified Unicode character; and 4) the
       result of this operation would mix Unicode and locale rules, which
       likely conflict.  Mixing of different rule types is forbidden, so
       the operation was not done; instead the result is the indicated
       value, which is the best available that uses entirely Unicode
       rules.  That turns out to almost always be the original character,
       unchanged.

       It is generally a bad idea to mix non-UTF-8 locales and Unicode,
       and this issue is one of the reasons why.  This warning is raised
       when Unicode rules would normally cause the result of this
       operation to contain a character that is in the range specified by
       the locale, 0..255, and hence is subject to the locale's rules, not
       Unicode's.

       If you are using locale purely for its characteristics related to
       things like its numeric and time formatting (and not "LC_CTYPE"),
       consider using a restricted form of the locale pragma (see "The
       "use locale" pragma" in perllocale) like
       ""uselocale':not_characters'"".

       Note that failed case-changing operations done as a result of case-
       insensitive "/i" regular expression matching will show up in this
       warning as having the "fc" operation (as that is what the regular
       expression engine calls behind the scenes.)

   Can't do waitpid with flags
       (F) This machine doesn't have either waitpid() or wait4(), so only
       waitpid() without flags is emulated.

   Can't emulate -%s on #! line
       (F) The #! line specifies a switch that doesn't make sense at this
       point.  For example, it'd be kind of silly to put a -x on the #!
       line.

   Can't %s %s-endian %ss on this platform
       (F) Your platform's byte-order is neither big-endian nor little-
       endian, or it has a very strange pointer size.  Packing and
       unpacking big- or little-endian floating point values and pointers
       may not be possible.  See "pack" in perlfunc.

   Can't exec "%s": %s
       (W exec) A system(), exec(), or piped open call could not execute
       the named program for the indicated reason.  Typical reasons
       include: the permissions were wrong on the file, the file wasn't
       found in $ENV{PATH}, the executable in question was compiled for
       another architecture, or the #! line in a script points to an
       interpreter that can't be run for similar reasons.  (Or maybe your
       system doesn't support #! at all.)

   Can't exec %s
       (F) Perl was trying to execute the indicated program for you
       because that's what the #! line said.  If that's not what you
       wanted, you may need to mention "perl" on the #! line somewhere.

   Can't execute %s
       (F) You used the -S switch, but the copies of the script to execute
       found in the PATH did not have correct permissions.

   Can't find an opnumber for "%s"
       (F) A string of a form "CORE::word" was given to prototype(), but
       there is no builtin with the name "word".

   Can't find label %s
       (F) You said to goto a label that isn't mentioned anywhere that
       it's possible for us to go to.  See "goto" in perlfunc.

   Can't find %s on PATH
       (F) You used the -S switch, but the script to execute could not be
       found in the PATH.

   Can't find %s on PATH, '.' not in PATH
       (F) You used the -S switch, but the script to execute could not be
       found in the PATH, or at least not with the correct permissions.
       The script exists in the current directory, but PATH prohibits
       running it.

   Can't find string terminator %s anywhere before EOF
       (F) Perl strings can stretch over multiple lines.  This message
       means that the closing delimiter was omitted.  Because bracketed
       quotes count nesting levels, the following is missing its final
       parenthesis:

           print q(The character '(' starts a side comment.);

       If you're getting this error from a here-document, you may have
       included unseen whitespace before or after your closing tag or
       there may not be a linebreak after it.  A good programmer's editor
       will have a way to help you find these characters (or lack of
       characters).  See perlop for the full details on here-documents.

   Can't find Unicode property definition "%s"
   Can't find Unicode property definition "%s" in regex; marked by <--
   HERE in m/%s/
       (F) The named property which you specified via "\p" or "\P" is not
       one known to Perl.  Perhaps you misspelled the name?  See
       "Properties accessible through \p{} and \P{}" in perluniprops for a
       complete list of available official properties.  If it is a user-
       defined property it must have been defined by the time the regular
       expression is matched.

       If you didn't mean to use a Unicode property, escape the "\p",
       either by "\\p" (just the "\p") or by "\Q\p" (the rest of the
       string, or until "\E").

   Can't fork: %s
       (F) A fatal error occurred while trying to fork while opening a
       pipeline.

   Can't fork, trying again in 5 seconds
       (W pipe) A fork in a piped open failed with EAGAIN and will be
       retried after five seconds.

   Can't get filespec - stale stat buffer?
       (S) A warning peculiar to VMS.  This arises because of the
       difference between access checks under VMS and under the Unix model
       Perl assumes.  Under VMS, access checks are done by filename,
       rather than by bits in the stat buffer, so that ACLs and other
       protections can be taken into account.  Unfortunately, Perl assumes
       that the stat buffer contains all the necessary information, and
       passes it, instead of the filespec, to the access-checking routine.
       It will try to retrieve the filespec using the device name and FID
       present in the stat buffer, but this works only if you haven't made
       a subsequent call to the CRTL stat() routine, because the device
       name is overwritten with each call.  If this warning appears, the
       name lookup failed, and the access-checking routine gave up and
       returned FALSE, just to be conservative.  (Note: The access-
       checking routine knows about the Perl "stat" operator and file
       tests, so you shouldn't ever see this warning in response to a Perl
       command; it arises only if some internal code takes stat buffers
       lightly.)

   Can't get pipe mailbox device name
       (P) An error peculiar to VMS.  After creating a mailbox to act as a
       pipe, Perl can't retrieve its name for later use.

   Can't get SYSGEN parameter value for MAXBUF
       (P) An error peculiar to VMS.  Perl asked $GETSYI how big you want
       your mailbox buffers to be, and didn't get an answer.

   Can't "goto" into the middle of a foreach loop
       (F) A "goto" statement was executed to jump into the middle of a
       foreach loop.  You can't get there from here.  See "goto" in
       perlfunc.

   Can't "goto" out of a pseudo block
       (F) A "goto" statement was executed to jump out of what might look
       like a block, except that it isn't a proper block.  This usually
       occurs if you tried to jump out of a sort() block or subroutine,
       which is a no-no.  See "goto" in perlfunc.

   Can't goto subroutine from an eval-%s
       (F) The "goto subroutine" call can't be used to jump out of an eval
       "string" or block.

   Can't goto subroutine from a sort sub (or similar callback)
       (F) The "goto subroutine" call can't be used to jump out of the
       comparison sub for a sort(), or from a similar callback (such as
       the reduce() function in List::Util).

   Can't goto subroutine outside a subroutine
       (F) The deeply magical "goto subroutine" call can only replace one
       subroutine call for another.  It can't manufacture one out of whole
       cloth.  In general you should be calling it out of only an AUTOLOAD
       routine anyway.  See "goto" in perlfunc.

   Can't ignore signal CHLD, forcing to default
       (W signal) Perl has detected that it is being run with the SIGCHLD
       signal (sometimes known as SIGCLD) disabled.  Since disabling this
       signal will interfere with proper determination of exit status of
       child processes, Perl has reset the signal to its default value.
       This situation typically indicates that the parent program under
       which Perl may be running (e.g. cron) is being very careless.

   Can't kill a non-numeric process ID
       (F) Process identifiers must be (signed) integers.  It is a fatal
       error to attempt to kill() an undefined, empty-string or otherwise
       non-numeric process identifier.

   Can't "last" outside a loop block
       (F) A "last" statement was executed to break out of the current
       block, except that there's this itty bitty problem called there
       isn't a current block.  Note that an "if" or "else" block doesn't
       count as a "loopish" block, as doesn't a block given to sort(),
       map() or grep().  You can usually double the curlies to get the
       same effect though, because the inner curlies will be considered a
       block that loops once.  See "last" in perlfunc.

   Can't linearize anonymous symbol table
       (F) Perl tried to calculate the method resolution order (MRO) of a
       package, but failed because the package stash has no name.

   Can't load '%s' for module %s
       (F) The module you tried to load failed to load a dynamic
       extension.  This may either mean that you upgraded your version of
       perl to one that is incompatible with your old dynamic extensions
       (which is known to happen between major versions of perl), or (more
       likely) that your dynamic extension was built against an older
       version of the library that is installed on your system.  You may
       need to rebuild your old dynamic extensions.

   Can't localize lexical variable %s
       (F) You used local on a variable name that was previously declared
       as a lexical variable using "my" or "state".  This is not allowed.
       If you want to localize a package variable of the same name,
       qualify it with the package name.

   Can't localize through a reference
       (F) You said something like "local $$ref", which Perl can't
       currently handle, because when it goes to restore the old value of
       whatever $ref pointed to after the scope of the local() is
       finished, it can't be sure that $ref will still be a reference.

   Can't locate %s
       (F) You said to "do" (or "require", or "use") a file that couldn't
       be found.  Perl looks for the file in all the locations mentioned
       in @INC, unless the file name included the full path to the file.
       Perhaps you need to set the PERL5LIB or PERL5OPT environment
       variable to say where the extra library is, or maybe the script
       needs to add the library name to @INC.  Or maybe you just
       misspelled the name of the file.  See "require" in perlfunc and
       lib.

   Can't locate auto/%s.al in @INC
       (F) A function (or method) was called in a package which allows
       autoload, but there is no function to autoload.  Most probable
       causes are a misprint in a function/method name or a failure to
       "AutoSplit" the file, say, by doing "make install".

   Can't locate loadable object for module %s in @INC
       (F) The module you loaded is trying to load an external library,
       like for example, foo.so or bar.dll, but the DynaLoader module was
       unable to locate this library.  See DynaLoader.

   Can't locate object method "%s" via package "%s"
       (F) You called a method correctly, and it correctly indicated a
       package functioning as a class, but that package doesn't define
       that particular method, nor does any of its base classes.  See
       perlobj.

   Can't locate object method "%s" via package "%s" (perhaps you forgot to
   load "%s"?)
       (F) You called a method on a class that did not exist, and the
       method could not be found in UNIVERSAL.  This often means that a
       method requires a package that has not been loaded.

   Can't locate package %s for @%s::ISA
       (W syntax) The @ISA array contained the name of another package
       that doesn't seem to exist.

   Can't locate PerlIO%s
       (F) You tried to use in open() a PerlIO layer that does not exist,
       e.g. open(FH, ">:nosuchlayer", "somefile").

   Can't make list assignment to %ENV on this system
       (F) List assignment to %ENV is not supported on some systems,
       notably VMS.

   Can't make loaded symbols global on this platform while loading %s
       (S) A module passed the flag 0x01 to DynaLoader::dl_load_file() to
       request that symbols from the stated file are made available
       globally within the process, but that functionality is not
       available on this platform.  Whilst the module likely will still
       work, this may prevent the perl interpreter from loading other XS-
       based extensions which need to link directly to functions defined
       in the C or XS code in the stated file.

   Can't modify %s in %s
       (F) You aren't allowed to assign to the item indicated, or
       otherwise try to change it, such as with an auto-increment.

   Can't modify nonexistent substring
       (P) The internal routine that does assignment to a substr() was
       handed a NULL.

   Can't modify non-lvalue subroutine call of &%s
       (F) Subroutines meant to be used in lvalue context should be
       declared as such.  See "Lvalue subroutines" in perlsub.

   Can't modify reference to %s in %s assignment
       (F) Only a limited number of constructs can be used as the argument
       to a reference constructor on the left-hand side of an assignment,
       and what you used was not one of them.  See "Assigning to
       References" in perlref.

   Can't modify reference to localized parenthesized array in list
   assignment
       (F) Assigning to "\local(@array)" or "\(local @array)" is not
       supported, as it is not clear exactly what it should do.  If you
       meant to make @array refer to some other array, use "\@array =
       \@other_array".  If you want to make the elements of @array aliases
       of the scalars referenced on the right-hand side, use "\(@array) =
       @scalar_refs".

   Can't modify reference to parenthesized hash in list assignment
       (F) Assigning to "\(%hash)" is not supported.  If you meant to make
       %hash refer to some other hash, use "\%hash = \%other_hash".  If
       you want to make the elements of %hash into aliases of the scalars
       referenced on the right-hand side, use a hash slice: "\@hash{@keys}
       = @those_scalar_refs".

   Can't msgrcv to read-only var
       (F) The target of a msgrcv must be modifiable to be used as a
       receive buffer.

   Can't "next" outside a loop block
       (F) A "next" statement was executed to reiterate the current block,
       but there isn't a current block.  Note that an "if" or "else" block
       doesn't count as a "loopish" block, as doesn't a block given to
       sort(), map() or grep().  You can usually double the curlies to get
       the same effect though, because the inner curlies will be
       considered a block that loops once.  See "next" in perlfunc.

   Can't open %s: %s
       (S inplace) The implicit opening of a file through use of the "<>"
       filehandle, either implicitly under the "-n" or "-p" command-line
       switches, or explicitly, failed for the indicated reason.  Usually
       this is because you don't have read permission for a file which you
       named on the command line.

       (F) You tried to call perl with the -e switch, but /dev/null (or
       your operating system's equivalent) could not be opened.

   Can't open a reference
       (W io) You tried to open a scalar reference for reading or writing,
       using the 3-arg open() syntax:

           open FH, '>', $ref;

       but your version of perl is compiled without perlio, and this form
       of open is not supported.

   Can't open bidirectional pipe
       (W pipe) You tried to say "open(CMD, "|cmd|")", which is not
       supported.  You can try any of several modules in the Perl library
       to do this, such as IPC::Open2.  Alternately, direct the pipe's
       output to a file using ">", and then read it in under a different
       file handle.

   Can't open error file %s as stderr
       (F) An error peculiar to VMS.  Perl does its own command line
       redirection, and couldn't open the file specified after '2>' or
       '2>>' on the command line for writing.

   Can't open input file %s as stdin
       (F) An error peculiar to VMS.  Perl does its own command line
       redirection, and couldn't open the file specified after '<' on the
       command line for reading.

   Can't open output file %s as stdout
       (F) An error peculiar to VMS.  Perl does its own command line
       redirection, and couldn't open the file specified after '>' or '>>'
       on the command line for writing.

   Can't open output pipe (name: %s)
       (P) An error peculiar to VMS.  Perl does its own command line
       redirection, and couldn't open the pipe into which to send data
       destined for stdout.

   Can't open perl script "%s": %s
       (F) The script you specified can't be opened for the indicated
       reason.

       If you're debugging a script that uses #!, and normally relies on
       the shell's $PATH search, the -S option causes perl to do that
       search, so you don't have to type the path or "`which
       $scriptname`".

   Can't read CRTL environ
       (S) A warning peculiar to VMS.  Perl tried to read an element of
       %ENV from the CRTL's internal environment array and discovered the
       array was missing.  You need to figure out where your CRTL
       misplaced its environ or define PERL_ENV_TABLES (see perlvms) so
       that environ is not searched.

   Can't redeclare "%s" in "%s"
       (F) A "my", "our" or "state" declaration was found within another
       declaration, such as "my ($x, my($y), $z)" or "our (my $x)".

   Can't "redo" outside a loop block
       (F) A "redo" statement was executed to restart the current block,
       but there isn't a current block.  Note that an "if" or "else" block
       doesn't count as a "loopish" block, as doesn't a block given to
       sort(), map() or grep().  You can usually double the curlies to get
       the same effect though, because the inner curlies will be
       considered a block that loops once.  See "redo" in perlfunc.

   Can't remove %s: %s, skipping file
       (S inplace) You requested an inplace edit without creating a backup
       file.  Perl was unable to remove the original file to replace it
       with the modified file.  The file was left unmodified.

   Can't rename %s to %s: %s, skipping file
       (S inplace) The rename done by the -i switch failed for some
       reason, probably because you don't have write permission to the
       directory.

   Can't reopen input pipe (name: %s) in binary mode
       (P) An error peculiar to VMS.  Perl thought stdin was a pipe, and
       tried to reopen it to accept binary data.  Alas, it failed.

   Can't represent character for Ox%X on this platform
       (F) There is a hard limit to how big a character code point can be
       due to the fundamental properties of UTF-8, especially on EBCDIC
       platforms.  The given code point exceeds that.  The only work-
       around is to not use such a large code point.

   Can't reset %ENV on this system
       (F) You called "reset('E')" or similar, which tried to reset all
       variables in the current package beginning with "E".  In the main
       package, that includes %ENV.  Resetting %ENV is not supported on
       some systems, notably VMS.

   Can't resolve method "%s" overloading "%s" in package "%s"
       (F)(P) Error resolving overloading specified by a method name (as
       opposed to a subroutine reference): no such method callable via the
       package.  If the method name is "???", this is an internal error.

   Can't return %s from lvalue subroutine
       (F) Perl detected an attempt to return illegal lvalues (such as
       temporary or readonly values) from a subroutine used as an lvalue.
       This is not allowed.

   Can't return outside a subroutine
       (F) The return statement was executed in mainline code, that is,
       where there was no subroutine call to return out of.  See perlsub.

   Can't return %s to lvalue scalar context
       (F) You tried to return a complete array or hash from an lvalue
       subroutine, but you called the subroutine in a way that made Perl
       think you meant to return only one value.  You probably meant to
       write parentheses around the call to the subroutine, which tell
       Perl that the call should be in list context.

   Can't stat script "%s"
       (P) For some reason you can't fstat() the script even though you
       have it open already.  Bizarre.

   Can't take log of %g
       (F) For ordinary real numbers, you can't take the logarithm of a
       negative number or zero.  There's a Math::Complex package that
       comes standard with Perl, though, if you really want to do that for
       the negative numbers.

   Can't take sqrt of %g
       (F) For ordinary real numbers, you can't take the square root of a
       negative number.  There's a Math::Complex package that comes
       standard with Perl, though, if you really want to do that.

   Can't undef active subroutine
       (F) You can't undefine a routine that's currently running.  You
       can, however, redefine it while it's running, and you can even
       undef the redefined subroutine while the old routine is running.
       Go figure.

   Can't upgrade %s (%d) to %d
       (P) The internal sv_upgrade routine adds "members" to an SV, making
       it into a more specialized kind of SV.  The top several SV types
       are so specialized, however, that they cannot be interconverted.
       This message indicates that such a conversion was attempted.

   Can't use '%c' after -mname
       (F) You tried to call perl with the -m switch, but you put
       something other than "=" after the module name.

   Can't use a hash as a reference
       (F) You tried to use a hash as a reference, as in "%foo->{"bar"}"
       or "%$ref->{"hello"}".  Versions of perl <= 5.22.0 used to allow
       this syntax, but shouldn't have.  This was deprecated in perl
       5.6.1.

   Can't use an array as a reference
       (F) You tried to use an array as a reference, as in "@foo->[23]" or
       "@$ref->[99]".  Versions of perl <= 5.22.0 used to allow this
       syntax, but shouldn't have.  This was deprecated in perl 5.6.1.

   Can't use anonymous symbol table for method lookup
       (F) The internal routine that does method lookup was handed a
       symbol table that doesn't have a name.  Symbol tables can become
       anonymous for example by undefining stashes: "undef
       %Some::Package::".

   Can't use an undefined value as %s reference
       (F) A value used as either a hard reference or a symbolic reference
       must be a defined value.  This helps to delurk some insidious
       errors.

   Can't use bareword ("%s") as %s ref while "strict refs" in use
       (F) Only hard references are allowed by "strict refs".  Symbolic
       references are disallowed.  See perlref.

   Can't use %! because Errno.pm is not available
       (F) The first time the "%!" hash is used, perl automatically loads
       the Errno.pm module.  The Errno module is expected to tie the %!
       hash to provide symbolic names for $! errno values.

   Can't use both '<' and '>' after type '%c' in %s
       (F) A type cannot be forced to have both big-endian and little-
       endian byte-order at the same time, so this combination of
       modifiers is not allowed.  See "pack" in perlfunc.

   Can't use 'defined(@array)' (Maybe you should just omit the defined()?)
       (F) defined() is not useful on arrays because it checks for an
       undefined scalar value.  If you want to see if the array is empty,
       just use "if (@array) { # not empty }" for example.

   Can't use 'defined(%hash)' (Maybe you should just omit the defined()?)
       (F) "defined()" is not usually right on hashes.

       Although "defined %hash" is false on a plain not-yet-used hash, it
       becomes true in several non-obvious circumstances, including
       iterators, weak references, stash names, even remaining true after
       "undef %hash".  These things make "defined %hash" fairly useless in
       practice, so it now generates a fatal error.

       If a check for non-empty is what you wanted then just put it in
       boolean context (see "Scalar values" in perldata):

           if (%hash) {
              # not empty
           }

       If you had "defined %Foo::Bar::QUUX" to check whether such a
       package variable exists then that's never really been reliable, and
       isn't a good way to enquire about the features of a package, or
       whether it's loaded, etc.

   Can't use %s for loop variable
       (P) The parser got confused when trying to parse a "foreach" loop.

   Can't use global %s in "%s"
       (F) You tried to declare a magical variable as a lexical variable.
       This is not allowed, because the magic can be tied to only one
       location (namely the global variable) and it would be incredibly
       confusing to have variables in your program that looked like
       magical variables but weren't.

   Can't use '%c' in a group with different byte-order in %s
       (F) You attempted to force a different byte-order on a type that is
       already inside a group with a byte-order modifier.  For example you
       cannot force little-endianness on a type that is inside a big-
       endian group.

   Can't use "my %s" in sort comparison
       (F) The global variables $a and $b are reserved for sort
       comparisons.  You mentioned $a or $b in the same line as the <=> or
       cmp operator, and the variable had earlier been declared as a
       lexical variable.  Either qualify the sort variable with the
       package name, or rename the lexical variable.

   Can't use %s ref as %s ref
       (F) You've mixed up your reference types.  You have to dereference
       a reference of the type needed.  You can use the ref() function to
       test the type of the reference, if need be.

   Can't use string ("%s") as %s ref while "strict refs" in use
   Can't use string ("%s"...) as %s ref while "strict refs" in use
       (F) You've told Perl to dereference a string, something which "use
       strict" blocks to prevent it happening accidentally.  See "Symbolic
       references" in perlref.  This can be triggered by an "@" or "$" in
       a double-quoted string immediately before interpolating a variable,
       for example in "user @$twitter_id", which says to treat the
       contents of $twitter_id as an array reference; use a "\" to have a
       literal "@" symbol followed by the contents of $twitter_id: "user
       \@$twitter_id".

   Can't use subscript on %s
       (F) The compiler tried to interpret a bracketed expression as a
       subscript.  But to the left of the brackets was an expression that
       didn't look like a hash or array reference, or anything else
       subscriptable.

   Can't use \%c to mean $%c in expression
       (W syntax) In an ordinary expression, backslash is a unary operator
       that creates a reference to its argument.  The use of backslash to
       indicate a backreference to a matched substring is valid only as
       part of a regular expression pattern.  Trying to do this in
       ordinary Perl code produces a value that prints out looking like
       SCALAR(0xdecaf).  Use the $1 form instead.

   Can't weaken a nonreference
       (F) You attempted to weaken something that was not a reference.
       Only references can be weakened.

   Can't "when" outside a topicalizer
       (F) You have used a when() block that is neither inside a "foreach"
       loop nor a "given" block.  (Note that this error is issued on exit
       from the "when" block, so you won't get the error if the match
       fails, or if you use an explicit "continue".)

   Can't x= to read-only value
       (F) You tried to repeat a constant value (often the undefined
       value) with an assignment operator, which implies modifying the
       value itself.  Perhaps you need to copy the value to a temporary,
       and repeat that.

   Character following "\c" must be printable ASCII
       (F) In "\cX", X must be a printable (non-control) ASCII character.

       Note that ASCII characters that don't map to control characters are
       discouraged, and will generate the warning (when enabled) ""\c%c"
       is more clearly written simply as "%s"".

   Character following \%c must be '{' or a single-character Unicode
   property name in regex; marked by <-- HERE in m/%s/
       (F) (In the above the %c is replaced by either "p" or "P".)  You
       specified something that isn't a legal Unicode property name.  Most
       Unicode properties are specified by "\p{...}".  But if the name is
       a single character one, the braces may be omitted.

   Character in 'C' format wrapped in pack
       (W pack) You said

           pack("C", $x)

       where $x is either less than 0 or more than 255; the "C" format is
       only for encoding native operating system characters (ASCII,
       EBCDIC, and so on) and not for Unicode characters, so Perl behaved
       as if you meant

           pack("C", $x & 255)

       If you actually want to pack Unicode codepoints, use the "U" format
       instead.

   Character in 'c' format wrapped in pack
       (W pack) You said

           pack("c", $x)

       where $x is either less than -128 or more than 127; the "c" format
       is only for encoding native operating system characters (ASCII,
       EBCDIC, and so on) and not for Unicode characters, so Perl behaved
       as if you meant

           pack("c", $x & 255);

       If you actually want to pack Unicode codepoints, use the "U" format
       instead.

   Character in '%c' format wrapped in unpack
       (W unpack) You tried something like

          unpack("H", "\x{2a1}")

       where the format expects to process a byte (a character with a
       value below 256), but a higher value was provided instead.  Perl
       uses the value modulus 256 instead, as if you had provided:

          unpack("H", "\x{a1}")

   Character in 'W' format wrapped in pack
       (W pack) You said

           pack("U0W", $x)

       where $x is either less than 0 or more than 255.  However,
       "U0"-mode expects all values to fall in the interval [0, 255], so
       Perl behaved as if you meant:

           pack("U0W", $x & 255)

   Character(s) in '%c' format wrapped in pack
       (W pack) You tried something like

          pack("u", "\x{1f3}b")

       where the format expects to process a sequence of bytes (character
       with a value below 256), but some of the characters had a higher
       value.  Perl uses the character values modulus 256 instead, as if
       you had provided:

          pack("u", "\x{f3}b")

   Character(s) in '%c' format wrapped in unpack
       (W unpack) You tried something like

          unpack("s", "\x{1f3}b")

       where the format expects to process a sequence of bytes (character
       with a value below 256), but some of the characters had a higher
       value.  Perl uses the character values modulus 256 instead, as if
       you had provided:

          unpack("s", "\x{f3}b")

   charnames alias definitions may not contain a sequence of multiple
   spaces
       (F) You defined a character name which had multiple space
       characters in a row.  Change them to single spaces.  Usually these
       names are defined in the ":alias" import argument to "use
       charnames", but they could be defined by a translator installed
       into $^H{charnames}.  See "CUSTOM ALIASES" in charnames.

   charnames alias definitions may not contain trailing white-space
       (F) You defined a character name which ended in a space character.
       Remove the trailing space(s).  Usually these names are defined in
       the ":alias" import argument to "use charnames", but they could be
       defined by a translator installed into $^H{charnames}.  See "CUSTOM
       ALIASES" in charnames.

   chdir() on unopened filehandle %s
       (W unopened) You tried chdir() on a filehandle that was never
       opened.

   "\c%c" is more clearly written simply as "%s"
       (W syntax) The "\cX" construct is intended to be a way to specify
       non-printable characters.  You used it for a printable one, which
       is better written as simply itself, perhaps preceded by a backslash
       for non-word characters.  Doing it the way you did is not portable
       between ASCII and EBCDIC platforms.

   Cloning substitution context is unimplemented
       (F) Creating a new thread inside the "s///" operator is not
       supported.

   closedir() attempted on invalid dirhandle %s
       (W io) The dirhandle you tried to close is either closed or not
       really a dirhandle.  Check your control flow.

   close() on unopened filehandle %s
       (W unopened) You tried to close a filehandle that was never opened.

   Closure prototype called
       (F) If a closure has attributes, the subroutine passed to an
       attribute handler is the prototype that is cloned when a new
       closure is created.  This subroutine cannot be called.

   \C no longer supported in regex; marked by <--HERE in m/%s/
       (F) The \C character class used to allow a match of single byte
       within a multi-byte utf-8 character, but was removed in v5.24 as it
       broke encapsulation and its implementation was extremely buggy.  If
       you really need to process the individual bytes, you probably want
       to convert your string to one where each underlying byte is stored
       as a character, with utf8::encode().

   Code missing after '/'
       (F) You had a (sub-)template that ends with a '/'.  There must be
       another template code following the slash.  See "pack" in perlfunc.

   Code point 0x%X is not Unicode, and not portable
       (S non_unicode) You had a code point that has never been in any
       standard, so it is likely that languages other than Perl will NOT
       understand it.  At one time, it was legal in some standards to have
       code points up to 0x7FFF_FFFF, but not higher, and this code point
       is higher.

       Acceptance of these code points is a Perl extension, and you should
       expect that nothing other than Perl can handle them; Perl itself on
       EBCDIC platforms before v5.24 does not handle them.

       Code points above 0xFFFF_FFFF require larger than a 32 bit word.

       Perl also makes no guarantees that the representation of these code
       points won't change at some point in the future, say when machines
       become available that have larger than a 64-bit word.  At that
       time, files written by an older Perl would require conversion
       before being readable by a newer Perl.

   Code point 0x%X is not Unicode, may not be portable
       (S non_unicode) You had a code point above the Unicode maximum of
       U+10FFFF.

       Perl allows strings to contain a superset of Unicode code points,
       but these may not be accepted by other languages/systems.  Further,
       even if these languages/systems accept these large code points,
       they may have chosen a different representation for them than the
       UTF-8-like one that Perl has, which would mean files are not
       exchangeable between them and Perl.

       On EBCDIC platforms, code points above 0x3FFF_FFFF have a different
       representation in Perl v5.24 than before, so any file containing
       these that was written before that version will require conversion
       before being readable by a later Perl.

   %s: Command not found
       (A) You've accidentally run your script through csh or another
       shell instead of Perl.  Check the #! line, or manually feed your
       script into Perl yourself.  The #! line at the top of your file
       could look like

         #!/usr/bin/perl -w

   Compilation failed in require
       (F) Perl could not compile a file specified in a "require"
       statement.  Perl uses this generic message when none of the errors
       that it encountered were severe enough to halt compilation
       immediately.

   Complex regular subexpression recursion limit (%d) exceeded
       (W regexp) The regular expression engine uses recursion in complex
       situations where back-tracking is required.  Recursion depth is
       limited to 32766, or perhaps less in architectures where the stack
       cannot grow arbitrarily.  ("Simple" and "medium" situations are
       handled without recursion and are not subject to a limit.)  Try
       shortening the string under examination; looping in Perl code (e.g.
       with "while") rather than in the regular expression engine; or
       rewriting the regular expression so that it is simpler or
       backtracks less.  (See perlfaq2 for information on Mastering
       Regular Expressions.)

   connect() on closed socket %s
       (W closed) You tried to do a connect on a closed socket.  Did you
       forget to check the return value of your socket() call?  See
       "connect" in perlfunc.

   Constant(%s): Call to &{$^H{%s}} did not return a defined value
       (F) The subroutine registered to handle constant overloading (see
       overload) or a custom charnames handler (see "CUSTOM TRANSLATORS"
       in charnames) returned an undefined value.

   Constant(%s): $^H{%s} is not defined
       (F) The parser found inconsistencies while attempting to define an
       overloaded constant.  Perhaps you forgot to load the corresponding
       overload pragma?

   Constant is not %s reference
       (F) A constant value (perhaps declared using the "use constant"
       pragma) is being dereferenced, but it amounts to the wrong type of
       reference.  The message indicates the type of reference that was
       expected.  This usually indicates a syntax error in dereferencing
       the constant value.  See "Constant Functions" in perlsub and
       constant.

   Constants from lexical variables potentially modified elsewhere are
   deprecated
       (D deprecated) You wrote something like

           my $var;
           $sub = sub () { $var };

       but $var is referenced elsewhere and could be modified after the
       "sub" expression is evaluated.  Either it is explicitly modified
       elsewhere ("$var = 3") or it is passed to a subroutine or to an
       operator like "printf" or "map", which may or may not modify the
       variable.

       Traditionally, Perl has captured the value of the variable at that
       point and turned the subroutine into a constant eligible for
       inlining.  In those cases where the variable can be modified
       elsewhere, this breaks the behavior of closures, in which the
       subroutine captures the variable itself, rather than its value, so
       future changes to the variable are reflected in the subroutine's
       return value.

       This usage is deprecated, because the behavior is likely to change
       in a future version of Perl.

       If you intended for the subroutine to be eligible for inlining,
       then make sure the variable is not referenced elsewhere, possibly
       by copying it:

           my $var2 = $var;
           $sub = sub () { $var2 };

       If you do want this subroutine to be a closure that reflects future
       changes to the variable that it closes over, add an explicit
       "return":

           my $var;
           $sub = sub () { return $var };

   Constant subroutine %s redefined
       (W redefine)(S) You redefined a subroutine which had previously
       been eligible for inlining.  See "Constant Functions" in perlsub
       for commentary and workarounds.

   Constant subroutine %s undefined
       (W misc) You undefined a subroutine which had previously been
       eligible for inlining.  See "Constant Functions" in perlsub for
       commentary and workarounds.

   Constant(%s) unknown
       (F) The parser found inconsistencies either while attempting to
       define an overloaded constant, or when trying to find the character
       name specified in the "\N{...}" escape.  Perhaps you forgot to load
       the corresponding overload pragma?

   :const is experimental
       (S experimental::const_attr) The "const" attribute is experimental.
       If you want to use the feature, disable the warning with "no
       warnings 'experimental::const_attr'", but know that in doing so you
       are taking the risk that your code may break in a future Perl
       version.

   :const is not permitted on named subroutines
       (F) The "const" attribute causes an anonymous subroutine to be run
       and its value captured at the time that it is cloned.  Named
       subroutines are not cloned like this, so the attribute does not
       make sense on them.

   Copy method did not return a reference
       (F) The method which overloads "=" is buggy.  See "Copy
       Constructor" in overload.

   &CORE::%s cannot be called directly
       (F) You tried to call a subroutine in the "CORE::" namespace with
       &foo syntax or through a reference.  Some subroutines in this
       package cannot yet be called that way, but must be called as
       barewords.  Something like this will work:

           BEGIN { *shove = \&CORE::push; }
           shove @array, 1,2,3; # pushes on to @array

   CORE::%s is not a keyword
       (F) The CORE:: namespace is reserved for Perl keywords.

   Corrupted regexp opcode %d > %d
       (P) This is either an error in Perl, or, if you're using one, your
       custom regular expression engine.  If not the latter, report the
       problem through the perlbug utility.

   corrupted regexp pointers
       (P) The regular expression engine got confused by what the regular
       expression compiler gave it.

   corrupted regexp program
       (P) The regular expression engine got passed a regexp program
       without a valid magic number.

   Corrupt malloc ptr 0x%x at 0x%x
       (P) The malloc package that comes with Perl had an internal
       failure.

   Count after length/code in unpack
       (F) You had an unpack template indicating a counted-length string,
       but you have also specified an explicit size for the string.  See
       "pack" in perlfunc.

   Deep recursion on anonymous subroutine
   Deep recursion on subroutine "%s"
       (W recursion) This subroutine has called itself (directly or
       indirectly) 100 times more than it has returned.  This probably
       indicates an infinite recursion, unless you're writing strange
       benchmark programs, in which case it indicates something else.

       This threshold can be changed from 100, by recompiling the perl
       binary, setting the C pre-processor macro "PERL_SUB_DEPTH_WARN" to
       the desired value.

   (?(DEFINE)....) does not allow branches in regex; marked by <--HERE in
   m/%s/
       (F) You used something like "(?(DEFINE)...|..)" which is illegal.
       The most likely cause of this error is that you left out a
       parenthesis inside of the "...." part.

       The <--HERE shows whereabouts in the regular expression the
       problem was discovered.

   %s defines neither package nor VERSION--version check failed
       (F) You said something like "use Module 42" but in the Module file
       there are neither package declarations nor a $VERSION.

   delete argument is index/value array slice, use array slice
       (F) You used index/value array slice syntax (%array[...]) as the
       argument to "delete".  You probably meant @array[...] with an @
       symbol instead.

   delete argument is key/value hash slice, use hash slice
       (F) You used key/value hash slice syntax (%hash{...}) as the
       argument to "delete".  You probably meant @hash{...} with an @
       symbol instead.

   delete argument is not a HASH or ARRAY element or slice
       (F) The argument to "delete" must be either a hash or array
       element, such as:

           $foo{$bar}
           $ref->{"susie"}[12]

       or a hash or array slice, such as:

           @foo[$bar, $baz, $xyzzy]
           @{$ref->[12]}{"susie", "queue"}

   Delimiter for here document is too long
       (F) In a here document construct like "<<FOO", the label "FOO" is
       too long for Perl to handle.  You have to be seriously twisted to
       write code that triggers this error.

   Deprecated use of my() in false conditional
       (D deprecated) You used a declaration similar to "my $x if 0".
       There has been a long-standing bug in Perl that causes a lexical
       variable not to be cleared at scope exit when its declaration
       includes a false conditional.  Some people have exploited this bug
       to achieve a kind of static variable.  Since we intend to fix this
       bug, we don't want people relying on this behavior.  You can
       achieve a similar static effect by declaring the variable in a
       separate block outside the function, eg

           sub f { my $x if 0; return $x++ }

       becomes

           { my $x; sub f { return $x++ } }

       Beginning with perl 5.10.0, you can also use "state" variables to
       have lexicals that are initialized only once (see feature):

           sub f { state $x; return $x++ }

   DESTROY created new reference to dead object '%s'
       (F) A DESTROY() method created a new reference to the object which
       is just being DESTROYed.  Perl is confused, and prefers to abort
       rather than to create a dangling reference.

   Did not produce a valid header
       See Server error.

   %s did not return a true value
       (F) A required (or used) file must return a true value to indicate
       that it compiled correctly and ran its initialization code
       correctly.  It's traditional to end such a file with a "1;", though
       any true value would do.  See "require" in perlfunc.

   (Did you mean &%s instead?)
       (W misc) You probably referred to an imported subroutine &FOO as
       $FOO or some such.

   (Did you mean "local" instead of "our"?)
       (W misc) Remember that "our" does not localize the declared global
       variable.  You have declared it again in the same lexical scope,
       which seems superfluous.

   (Did you mean $ or @ instead of %?)
       (W) You probably said %hash{$key} when you meant $hash{$key} or
       @hash{@keys}.  On the other hand, maybe you just meant %hash and
       got carried away.

   Died
       (F) You passed die() an empty string (the equivalent of "die """)
       or you called it with no args and $@ was empty.

   Document contains no data
       See Server error.

   %s does not define %s::VERSION--version check failed
       (F) You said something like "use Module 42" but the Module did not
       define a $VERSION.

   '/' does not take a repeat count
       (F) You cannot put a repeat count of any kind right after the '/'
       code.  See "pack" in perlfunc.

   Don't know how to get file name
       (P) "PerlIO_getname", a perl internal I/O function specific to VMS,
       was somehow called on another platform.  This should not happen.

   Don't know how to handle magic of type \%o
       (P) The internal handling of magical variables has been cursed.

   do_study: out of memory
       (P) This should have been caught by safemalloc() instead.

   (Do you need to predeclare %s?)
       (S syntax) This is an educated guess made in conjunction with the
       message "%s found where operator expected".  It often means a
       subroutine or module name is being referenced that hasn't been
       declared yet.  This may be because of ordering problems in your
       file, or because of a missing "sub", "package", "require", or "use"
       statement.  If you're referencing something that isn't defined yet,
       you don't actually have to define the subroutine or package before
       the current location.  You can use an empty "sub foo;" or "package
       FOO;" to enter a "forward" declaration.

   dump() better written as CORE::dump()
       (W misc) You used the obsolescent "dump()" built-in function,
       without fully qualifying it as "CORE::dump()".  Maybe it's a typo.
       See "dump" in perlfunc.

   dump is not supported
       (F) Your machine doesn't support dump/undump.

   Duplicate free() ignored
       (S malloc) An internal routine called free() on something that had
       already been freed.

   Duplicate modifier '%c' after '%c' in %s
       (W unpack) You have applied the same modifier more than once after
       a type in a pack template.  See "pack" in perlfunc.

   elseif should be elsif
       (S syntax) There is no keyword "elseif" in Perl because Larry
       thinks it's ugly.  Your code will be interpreted as an attempt to
       call a method named "elseif" for the class returned by the
       following block.  This is unlikely to be what you want.

   Empty \%c in regex; marked by <--HERE in m/%s/
   Empty \%c{} in regex; marked by <--HERE in m/%s/
       (F) "\p" and "\P" are used to introduce a named Unicode property,
       as described in perlunicode and perlre.  You used "\p" or "\P" in a
       regular expression without specifying the property name.

   entering effective %s failed
       (F) While under the "use filetest" pragma, switching the real and
       effective uids or gids failed.

   %ENV is aliased to %s
       (F) You're running under taint mode, and the %ENV variable has been
       aliased to another hash, so it doesn't reflect anymore the state of
       the program's environment.  This is potentially insecure.

   Error converting file specification %s
       (F) An error peculiar to VMS.  Because Perl may have to deal with
       file specifications in either VMS or Unix syntax, it converts them
       to a single form when it must operate on them directly.  Either
       you've passed an invalid file specification to Perl, or you've
       found a case the conversion routines don't handle.  Drat.

   Eval-group in insecure regular expression
       (F) Perl detected tainted data when trying to compile a regular
       expression that contains the "(?{ ... })" zero-width assertion,
       which is unsafe.  See "(?{ code })" in perlre, and perlsec.

   Eval-group not allowed at runtime, use re 'eval' in regex m/%s/
       (F) Perl tried to compile a regular expression containing the "(?{
       ... })" zero-width assertion at run time, as it would when the
       pattern contains interpolated values.  Since that is a security
       risk, it is not allowed.  If you insist, you may still do this by
       using the "re 'eval'" pragma or by explicitly building the pattern
       from an interpolated string at run time and using that in an
       eval().  See "(?{ code })" in perlre.

   Eval-group not allowed, use re 'eval' in regex m/%s/
       (F) A regular expression contained the "(?{ ... })" zero-width
       assertion, but that construct is only allowed when the "use re
       'eval'" pragma is in effect.  See "(?{ code })" in perlre.

   EVAL without pos change exceeded limit in regex; marked by <--HERE in
   m/%s/
       (F) You used a pattern that nested too many EVAL calls without
       consuming any text.  Restructure the pattern so that text is
       consumed.

       The <--HERE shows whereabouts in the regular expression the
       problem was discovered.

   Excessively long <> operator
       (F) The contents of a <> operator may not exceed the maximum size
       of a Perl identifier.  If you're just trying to glob a long list of
       filenames, try using the glob() operator, or put the filenames into
       a variable and glob that.

   exec? I'm not *that* kind of operating system
       (F) The "exec" function is not implemented on some systems, e.g.,
       Symbian OS.  See perlport.

   Execution of %s aborted due to compilation errors.
       (F) The final summary message when a Perl compilation fails.

   exists argument is not a HASH or ARRAY element or a subroutine
       (F) The argument to "exists" must be a hash or array element or a
       subroutine with an ampersand, such as:

           $foo{$bar}
           $ref->{"susie"}[12]
           &do_something

   exists argument is not a subroutine name
       (F) The argument to "exists" for "exists &sub" must be a subroutine
       name, and not a subroutine call.  "exists &sub()" will generate
       this error.

   Exiting eval via %s
       (W exiting) You are exiting an eval by unconventional means, such
       as a goto, or a loop control statement.

   Exiting format via %s
       (W exiting) You are exiting a format by unconventional means, such
       as a goto, or a loop control statement.

   Exiting pseudo-block via %s
       (W exiting) You are exiting a rather special block construct (like
       a sort block or subroutine) by unconventional means, such as a
       goto, or a loop control statement.  See "sort" in perlfunc.

   Exiting subroutine via %s
       (W exiting) You are exiting a subroutine by unconventional means,
       such as a goto, or a loop control statement.

   Exiting substitution via %s
       (W exiting) You are exiting a substitution by unconventional means,
       such as a return, a goto, or a loop control statement.

   Expecting close bracket in regex; marked by <--HERE in m/%s/
       (F) You wrote something like

        (?13

       to denote a capturing group of the form "(?PARNO)", but omitted the
       ")".

   Expecting '(?flags:(?[...' in regex; marked by <--HERE in m/%s/
       (F) The "(?[...])" extended character class regular expression
       construct only allows character classes (including character class
       escapes like "\d"), operators, and parentheses.  The one exception
       is "(?flags:...)"  containing at least one flag and exactly one
       "(?[...])" construct.  This allows a regular expression containing
       just "(?[...])" to be interpolated.  If you see this error message,
       then you probably have some other "(?...)" construct inside your
       character class.  See "Extended Bracketed Character Classes" in
       perlrecharclass.

   Experimental aliasing via reference not enabled
       (F) To do aliasing via references, you must first enable the
       feature:

           no warnings "experimental::refaliasing";
           use feature "refaliasing";
           \$x = \$y;

   Experimental %s on scalar is now forbidden
       (F) An experimental feature added in Perl 5.14 allowed "each",
       "keys", "push", "pop", "shift", "splice", "unshift", and "values"
       to be called with a scalar argument.  This experiment is considered
       unsuccessful, and has been removed.  The "postderef" feature may
       meet your needs better.

   Experimental subroutine signatures not enabled
       (F) To use subroutine signatures, you must first enable them:

           no warnings "experimental::signatures";
           use feature "signatures";
           sub foo ($left, $right) { ... }

   Experimental "%s" subs not enabled
       (F) To use lexical subs, you must first enable them:

           no warnings 'experimental::lexical_subs';
           use feature 'lexical_subs';
           my sub foo { ... }

   Explicit blessing to '' (assuming package main)
       (W misc) You are blessing a reference to a zero length string.
       This has the effect of blessing the reference into the package
       main.  This is usually not what you want.  Consider providing a
       default target package, e.g. bless($ref, $p || 'MyPackage');

   %s: Expression syntax
       (A) You've accidentally run your script through csh instead of
       Perl.  Check the #! line, or manually feed your script into Perl
       yourself.

   %s failed--call queue aborted
       (F) An untrapped exception was raised while executing a UNITCHECK,
       CHECK, INIT, or END subroutine.  Processing of the remainder of the
       queue of such routines has been prematurely ended.

   Failed to close in-place edit file %s: %s
       (F) Closing an output file from in-place editing, as with the "-i"
       command-line switch, failed.

   False [] range "%s" in regex; marked by <--HERE in m/%s/
       (W regexp)(F) A character class range must start and end at a
       literal character, not another character class like "\d" or
       "[:alpha:]".  The "-" in your false range is interpreted as a
       literal "-".  In a "(?[...])"  construct, this is an error, rather
       than a warning.  Consider quoting the "-", "\-".  The <--HERE
       shows whereabouts in the regular expression the problem was
       discovered.  See perlre.

   Fatal VMS error (status=%d) at %s, line %d
       (P) An error peculiar to VMS.  Something untoward happened in a VMS
       system service or RTL routine; Perl's exit status should provide
       more details.  The filename in "at %s" and the line number in "line
       %d" tell you which section of the Perl source code is distressed.

   fcntl is not implemented
       (F) Your machine apparently doesn't implement fcntl().  What is
       this, a PDP-11 or something?

   FETCHSIZE returned a negative value
       (F) A tied array claimed to have a negative number of elements,
       which is not possible.

   Field too wide in 'u' format in pack
       (W pack) Each line in an uuencoded string starts with a length
       indicator which can't encode values above 63.  So there is no point
       in asking for a line length bigger than that.  Perl will behave as
       if you specified "u63" as the format.

   Filehandle %s opened only for input
       (W io) You tried to write on a read-only filehandle.  If you
       intended it to be a read-write filehandle, you needed to open it
       with "+<" or "+>" or "+>>" instead of with "<" or nothing.  If you
       intended only to write the file, use ">" or ">>".  See "open" in
       perlfunc.

   Filehandle %s opened only for output
       (W io) You tried to read from a filehandle opened only for writing,
       If you intended it to be a read/write filehandle, you needed to
       open it with "+<" or "+>" or "+>>" instead of with ">".  If you
       intended only to read from the file, use "<".  See "open" in
       perlfunc.  Another possibility is that you attempted to open
       filedescriptor 0 (also known as STDIN) for output (maybe you closed
       STDIN earlier?).

   Filehandle %s reopened as %s only for input
       (W io) You opened for reading a filehandle that got the same
       filehandle id as STDOUT or STDERR.  This occurred because you
       closed STDOUT or STDERR previously.

   Filehandle STDIN reopened as %s only for output
       (W io) You opened for writing a filehandle that got the same
       filehandle id as STDIN.  This occurred because you closed STDIN
       previously.

   Final $ should be \$ or $name
       (F) You must now decide whether the final $ in a string was meant
       to be a literal dollar sign, or was meant to introduce a variable
       name that happens to be missing.  So you have to put either the
       backslash or the name.

   flock() on closed filehandle %s
       (W closed) The filehandle you're attempting to flock() got itself
       closed some time before now.  Check your control flow.  flock()
       operates on filehandles.  Are you attempting to call flock() on a
       dirhandle by the same name?

   Format not terminated
       (F) A format must be terminated by a line with a solitary dot.
       Perl got to the end of your file without finding such a line.

   Format %s redefined
       (W redefine) You redefined a format.  To suppress this warning, say

           {
               no warnings 'redefine';
               eval "format NAME =...";
           }

   Found = in conditional, should be ==
       (W syntax) You said

           if ($foo = 123)

       when you meant

           if ($foo == 123)

       (or something like that).

   %s found where operator expected
       (S syntax) The Perl lexer knows whether to expect a term or an
       operator.  If it sees what it knows to be a term when it was
       expecting to see an operator, it gives you this warning.  Usually
       it indicates that an operator or delimiter was omitted, such as a
       semicolon.

   gdbm store returned %d, errno %d, key "%s"
       (S) A warning from the GDBM_File extension that a store failed.

   gethostent not implemented
       (F) Your C library apparently doesn't implement gethostent(),
       probably because if it did, it'd feel morally obligated to return
       every hostname on the Internet.

   get%sname() on closed socket %s
       (W closed) You tried to get a socket or peer socket name on a
       closed socket.  Did you forget to check the return value of your
       socket() call?

   getpwnam returned invalid UIC %#o for user "%s"
       (S) A warning peculiar to VMS.  The call to "sys$getuai" underlying
       the "getpwnam" operator returned an invalid UIC.

   getsockopt() on closed socket %s
       (W closed) You tried to get a socket option on a closed socket.
       Did you forget to check the return value of your socket() call?
       See "getsockopt" in perlfunc.

   given is experimental
       (S experimental::smartmatch) "given" depends on smartmatch, which
       is experimental, so its behavior may change or even be removed in
       any future release of perl.  See the explanation under
       "Experimental Details on given and when" in perlsyn.

   Global symbol "%s" requires explicit package name (did you forget to
   declare "my %s"?)
       (F) You've said "use strict" or "use strict vars", which indicates
       that all variables must either be lexically scoped (using "my" or
       "state"), declared beforehand using "our", or explicitly qualified
       to say which package the global variable is in (using "::").

   glob failed (%s)
       (S glob) Something went wrong with the external program(s) used for
       "glob" and "<*.c>".  Usually, this means that you supplied a "glob"
       pattern that caused the external program to fail and exit with a
       nonzero status.  If the message indicates that the abnormal exit
       resulted in a coredump, this may also mean that your csh (C shell)
       is broken.  If so, you should change all of the csh-related
       variables in config.sh:  If you have tcsh, make the variables refer
       to it as if it were csh (e.g. "full_csh='/usr/bin/tcsh'");
       otherwise, make them all empty (except that "d_csh" should be
       'undef') so that Perl will think csh is missing.  In either case,
       after editing config.sh, run "./Configure -S" and rebuild Perl.

   Glob not terminated
       (F) The lexer saw a left angle bracket in a place where it was
       expecting a term, so it's looking for the corresponding right angle
       bracket, and not finding it.  Chances are you left some needed
       parentheses out earlier in the line, and you really meant a "less
       than".

   gmtime(%f) failed
       (W overflow) You called "gmtime" with a number that it could not
       handle: too large, too small, or NaN.  The returned value is
       "undef".

   gmtime(%f) too large
       (W overflow) You called "gmtime" with a number that was larger than
       it can reliably handle and "gmtime" probably returned the wrong
       date.  This warning is also triggered with NaN (the special not-a-
       number value).

   gmtime(%f) too small
       (W overflow) You called "gmtime" with a number that was smaller
       than it can reliably handle and "gmtime" probably returned the
       wrong date.

   Got an error from DosAllocMem
       (P) An error peculiar to OS/2.  Most probably you're using an
       obsolete version of Perl, and this should not happen anyway.

   goto must have label
       (F) Unlike with "next" or "last", you're not allowed to goto an
       unspecified destination.  See "goto" in perlfunc.

   Goto undefined subroutine%s
       (F) You tried to call a subroutine with "goto &sub" syntax, but the
       indicated subroutine hasn't been defined, or if it was, it has
       since been undefined.

   Group name must start with a non-digit word character in regex; marked
   by <--HERE in m/%s/
       (F) Group names must follow the rules for perl identifiers, meaning
       they must start with a non-digit word character.  A common cause of
       this error is using (?&0) instead of (?0).  See perlre.

   ()-group starts with a count
       (F) A ()-group started with a count.  A count is supposed to follow
       something: a template character or a ()-group.  See "pack" in
       perlfunc.

   %s had compilation errors.
       (F) The final summary message when a "perl -c" fails.

   Had to create %s unexpectedly
       (S internal) A routine asked for a symbol from a symbol table that
       ought to have existed already, but for some reason it didn't, and
       had to be created on an emergency basis to prevent a core dump.

   %s has too many errors
       (F) The parser has given up trying to parse the program after 10
       errors.  Further error messages would likely be uninformative.

   Having more than one /%c regexp modifier is deprecated
       (D deprecated, regexp) You used the indicated regular expression
       pattern modifier at least twice in a string of modifiers.  It is
       deprecated to do this with this particular modifier, to allow
       future extensions to the Perl language.

   Hexadecimal float: exponent overflow
       (W overflow) The hexadecimal floating point has a larger exponent
       than the floating point supports.

   Hexadecimal float: exponent underflow
       (W overflow) The hexadecimal floating point has a smaller exponent
       than the floating point supports.

   Hexadecimal float: internal error (%s)
       (F) Something went horribly bad in hexadecimal float handling.

   Hexadecimal float: mantissa overflow
       (W overflow) The hexadecimal floating point literal had more bits
       in the mantissa (the part between the 0x and the exponent, also
       known as the fraction or the significand) than the floating point
       supports.

   Hexadecimal float: precision loss
       (W overflow) The hexadecimal floating point had internally more
       digits than could be output.  This can be caused by unsupported
       long double formats, or by 64-bit integers not being available
       (needed to retrieve the digits under some configurations).

   Hexadecimal float: unsupported long double format
       (F) You have configured Perl to use long doubles but the internals
       of the long double format are unknown; therefore the hexadecimal
       float output is impossible.

   Hexadecimal number > 0xffffffff non-portable
       (W portable) The hexadecimal number you specified is larger than
       2**32-1 (4294967295) and therefore non-portable between systems.
       See perlport for more on portability concerns.

   Identifier too long
       (F) Perl limits identifiers (names for variables, functions, etc.)
       to about 250 characters for simple names, and somewhat more for
       compound names (like $A::B).  You've exceeded Perl's limits.
       Future versions of Perl are likely to eliminate these arbitrary
       limitations.

   Ignoring zero length \N{} in character class in regex; marked by
   <--HERE in m/%s/
       (W regexp) Named Unicode character escapes ("\N{...}") may return a
       zero-length sequence.  When such an escape is used in a character
       class its behavior is not well defined.  Check that the correct
       escape has been used, and the correct charname handler is in scope.

   Illegal binary digit %s
       (F) You used a digit other than 0 or 1 in a binary number.

   Illegal binary digit %s ignored
       (W digit) You may have tried to use a digit other than 0 or 1 in a
       binary number.  Interpretation of the binary number stopped before
       the offending digit.

   Illegal character after '_' in prototype for %s : %s
       (W illegalproto) An illegal character was found in a prototype
       declaration.  The '_' in a prototype must be followed by a ';',
       indicating the rest of the parameters are optional, or one of '@'
       or '%', since those two will accept 0 or more final parameters.

   Illegal character \%o (carriage return)
       (F) Perl normally treats carriage returns in the program text as it
       would any other whitespace, which means you should never see this
       error when Perl was built using standard options.  For some reason,
       your version of Perl appears to have been built without this
       support.  Talk to your Perl administrator.

   Illegal character in prototype for %s : %s
       (W illegalproto) An illegal character was found in a prototype
       declaration.  Legal characters in prototypes are $, @, %, *, ;, [,
       ], &, \, and +.  Perhaps you were trying to write a subroutine
       signature but didn't enable that feature first ("use feature
       'signatures'"), so your signature was instead interpreted as a bad
       prototype.

   Illegal declaration of anonymous subroutine
       (F) When using the "sub" keyword to construct an anonymous
       subroutine, you must always specify a block of code.  See perlsub.

   Illegal declaration of subroutine %s
       (F) A subroutine was not declared correctly.  See perlsub.

   Illegal division by zero
       (F) You tried to divide a number by 0.  Either something was wrong
       in your logic, or you need to put a conditional in to guard against
       meaningless input.

   Illegal hexadecimal digit %s ignored
       (W digit) You may have tried to use a character other than 0 - 9 or
       A - F, a - f in a hexadecimal number.  Interpretation of the
       hexadecimal number stopped before the illegal character.

   Illegal modulus zero
       (F) You tried to divide a number by 0 to get the remainder.  Most
       numbers don't take to this kindly.

   Illegal number of bits in vec
       (F) The number of bits in vec() (the third argument) must be a
       power of two from 1 to 32 (or 64, if your platform supports that).

   Illegal octal digit %s
       (F) You used an 8 or 9 in an octal number.

   Illegal octal digit %s ignored
       (W digit) You may have tried to use an 8 or 9 in an octal number.
       Interpretation of the octal number stopped before the 8 or 9.

   Illegal pattern in regex; marked by <--HERE in m/%s/
       (F) You wrote something like

        (?+foo)

       The "+" is valid only when followed by digits, indicating a
       capturing group.  See "(?PARNO)".

   Illegal suidscript
       (F) The script run under suidperl was somehow illegal.

   Illegal switch in PERL5OPT: -%c
       (X) The PERL5OPT environment variable may only be used to set the
       following switches: -[CDIMUdmtw].

   Illegal user-defined property name
       (F) You specified a Unicode-like property name in a regular
       expression pattern (using "\p{}" or "\P{}") that Perl knows isn't
       an official Unicode property, and was likely meant to be a user-
       defined property name, but it can't be one of those, as they must
       begin with either "In" or "Is".  Check the spelling.  See also
       "Can't find Unicode property definition "%s"".

   Ill-formed CRTL environ value "%s"
       (W internal) A warning peculiar to VMS.  Perl tried to read the
       CRTL's internal environ array, and encountered an element without
       the "=" delimiter used to separate keys from values.  The element
       is ignored.

   Ill-formed message in prime_env_iter: |%s|
       (W internal) A warning peculiar to VMS.  Perl tried to read a
       logical name or CLI symbol definition when preparing to iterate
       over %ENV, and didn't see the expected delimiter between key and
       value, so the line was ignored.

   (in cleanup) %s
       (W misc) This prefix usually indicates that a DESTROY() method
       raised the indicated exception.  Since destructors are usually
       called by the system at arbitrary points during execution, and
       often a vast number of times, the warning is issued only once for
       any number of failures that would otherwise result in the same
       message being repeated.

       Failure of user callbacks dispatched using the "G_KEEPERR" flag
       could also result in this warning.  See "G_KEEPERR" in perlcall.

   Incomplete expression within '(?[ ])' in regex; marked by <--HERE in
   m/%s/
       (F) There was a syntax error within the "(?[ ])".  This can happen
       if the expression inside the construct was completely empty, or if
       there are too many or few operands for the number of operators.
       Perl is not smart enough to give you a more precise indication as
       to what is wrong.

   Inconsistent hierarchy during C3 merge of class '%s': merging failed on
   parent '%s'
       (F) The method resolution order (MRO) of the given class is not
       C3-consistent, and you have enabled the C3 MRO for this class.  See
       the C3 documentation in mro for more information.

   Infinite recursion in regex
       (F) You used a pattern that references itself without consuming any
       input text.  You should check the pattern to ensure that recursive
       patterns either consume text or fail.

   Initialization of state variables in list context currently forbidden
       (F) Currently the implementation of "state" only permits the
       initialization of scalar variables in scalar context.  Re-write
       "state ($a) = 42" as "state $a = 42" to change from list to scalar
       context.  Constructions such as "state (@a) = foo()" will be
       supported in a future perl release.

   %%s[%s] in scalar context better written as $%s[%s]
       (W syntax) In scalar context, you've used an array index/value
       slice (indicated by %) to select a single element of an array.
       Generally it's better to ask for a scalar value (indicated by $).
       The difference is that $foo[&bar] always behaves like a scalar,
       both in the value it returns and when evaluating its argument,
       while %foo[&bar] provides a list context to its subscript, which
       can do weird things if you're expecting only one subscript.  When
       called in list context, it also returns the index (what &bar
       returns) in addition to the value.

   %%s{%s} in scalar context better written as $%s{%s}
       (W syntax) In scalar context, you've used a hash key/value slice
       (indicated by %) to select a single element of a hash.  Generally
       it's better to ask for a scalar value (indicated by $).  The
       difference is that $foo{&bar} always behaves like a scalar, both in
       the value it returns and when evaluating its argument, while
       @foo{&bar} and provides a list context to its subscript, which can
       do weird things if you're expecting only one subscript.  When
       called in list context, it also returns the key in addition to the
       value.

   Insecure dependency in %s
       (F) You tried to do something that the tainting mechanism didn't
       like.  The tainting mechanism is turned on when you're running
       setuid or setgid, or when you specify -T to turn it on explicitly.
       The tainting mechanism labels all data that's derived directly or
       indirectly from the user, who is considered to be unworthy of your
       trust.  If any such data is used in a "dangerous" operation, you
       get this error.  See perlsec for more information.

   Insecure directory in %s
       (F) You can't use system(), exec(), or a piped open in a setuid or
       setgid script if $ENV{PATH} contains a directory that is writable
       by the world.  Also, the PATH must not contain any relative
       directory.  See perlsec.

   Insecure $ENV{%s} while running %s
       (F) You can't use system(), exec(), or a piped open in a setuid or
       setgid script if any of $ENV{PATH}, $ENV{IFS}, $ENV{CDPATH},
       $ENV{ENV}, $ENV{BASH_ENV} or $ENV{TERM} are derived from data
       supplied (or potentially supplied) by the user.  The script must
       set the path to a known value, using trustworthy data.  See
       perlsec.

   Insecure user-defined property %s
       (F) Perl detected tainted data when trying to compile a regular
       expression that contains a call to a user-defined character
       property function, i.e. "\p{IsFoo}" or "\p{InFoo}".  See "User-
       Defined Character Properties" in perlunicode and perlsec.

   Integer overflow in format string for %s
       (F) The indexes and widths specified in the format string of
       "printf()" or "sprintf()" are too large.  The numbers must not
       overflow the size of integers for your architecture.

   Integer overflow in %s number
       (S overflow) The hexadecimal, octal or binary number you have
       specified either as a literal or as an argument to hex() or oct()
       is too big for your architecture, and has been converted to a
       floating point number.  On a 32-bit architecture the largest
       hexadecimal, octal or binary number representable without overflow
       is 0xFFFFFFFF, 037777777777, or 0b11111111111111111111111111111111
       respectively.  Note that Perl transparently promotes all numbers to
       a floating point representation internally--subject to loss of
       precision errors in subsequent operations.

   Integer overflow in srand
       (S overflow) The number you have passed to srand is too big to fit
       in your architecture's integer representation.  The number has been
       replaced with the largest integer supported (0xFFFFFFFF on 32-bit
       architectures).  This means you may be getting less randomness than
       you expect, because different random seeds above the maximum will
       return the same sequence of random numbers.

   Integer overflow in version
   Integer overflow in version %d
       (W overflow) Some portion of a version initialization is too large
       for the size of integers for your architecture.  This is not a
       warning because there is no rational reason for a version to try
       and use an element larger than typically 2**32.  This is usually
       caused by trying to use some odd mathematical operation as a
       version, like 100/9.

   Internal disaster in regex; marked by <--HERE in m/%s/
       (P) Something went badly wrong in the regular expression parser.
       The <--HERE shows whereabouts in the regular expression the
       problem was discovered.

   Internal inconsistency in tracking vforks
       (S) A warning peculiar to VMS.  Perl keeps track of the number of
       times you've called "fork" and "exec", to determine whether the
       current call to "exec" should affect the current script or a
       subprocess (see "exec LIST" in perlvms).  Somehow, this count has
       become scrambled, so Perl is making a guess and treating this
       "exec" as a request to terminate the Perl script and execute the
       specified command.

   internal %<num>p might conflict with future printf extensions
       (S internal) Perl's internal routine that handles "printf" and
       "sprintf" formatting follows a slightly different set of rules when
       called from C or XS code.  Specifically, formats consisting of
       digits followed by "p" (e.g., "%7p") are reserved for future use.
       If you see this message, then an XS module tried to call that
       routine with one such reserved format.

   Internal urp in regex; marked by <--HERE in m/%s/
       (P) Something went badly awry in the regular expression parser.
       The <--HERE shows whereabouts in the regular expression the
       problem was discovered.

   %s (...) interpreted as function
       (W syntax) You've run afoul of the rule that says that any list
       operator followed by parentheses turns into a function, with all
       the list operators arguments found inside the parentheses.  See
       "Terms and List Operators (Leftward)" in perlop.

   In '(?...)', the '(' and '?' must be adjacent in regex; marked by
   <--HERE in m/%s/
       (F) The two-character sequence "(?" in this context in a regular
       expression pattern should be an indivisible token, with nothing
       intervening between the "(" and the "?", but you separated them
       with whitespace.

   Invalid %s attribute: %s
       (F) The indicated attribute for a subroutine or variable was not
       recognized by Perl or by a user-supplied handler.  See attributes.

   Invalid %s attributes: %s
       (F) The indicated attributes for a subroutine or variable were not
       recognized by Perl or by a user-supplied handler.  See attributes.

   Invalid character in charnames alias definition; marked by <--HERE in
   '%s
       (F) You tried to create a custom alias for a character name, with
       the ":alias" option to "use charnames" and the specified character
       in the indicated name isn't valid.  See "CUSTOM ALIASES" in
       charnames.

   Invalid \0 character in %s for %s: %s\0%s
       (W syscalls) Embedded \0 characters in pathnames or other system
       call arguments produce a warning as of 5.20.  The parts after the
       \0 were formerly ignored by system calls.

   Invalid character in \N{...}; marked by <--HERE in \N{%s}
       (F) Only certain characters are valid for character names.  The
       indicated one isn't.  See "CUSTOM ALIASES" in charnames.

   Invalid conversion in %s: "%s"
       (W printf) Perl does not understand the given format conversion.
       See "sprintf" in perlfunc.

   Invalid escape in the specified encoding in regex; marked by <--HERE
   in m/%s/
       (W regexp)(F) The numeric escape (for example "\xHH") of value <
       256 didn't correspond to a single character through the conversion
       from the encoding specified by the encoding pragma.  The escape was
       replaced with REPLACEMENT CHARACTER (U+FFFD) instead, except within
       "(?[])", where it is a fatal error.  The <--HERE shows
       whereabouts in the regular expression the escape was discovered.

   Invalid hexadecimal number in \N{U+...}
   Invalid hexadecimal number in \N{U+...} in regex; marked by <--HERE in
   m/%s/
       (F) The character constant represented by "..." is not a valid
       hexadecimal number.  Either it is empty, or you tried to use a
       character other than 0 - 9 or A - F, a - f in a hexadecimal number.

   Invalid module name %s with -%c option: contains single ':'
       (F) The module argument to perl's -m and -M command-line options
       cannot contain single colons in the module name, but only in the
       arguments after "=".  In other words, -MFoo::Bar=:baz is ok, but
       -MFoo:Bar=baz is not.

   Invalid mro name: '%s'
       (F) You tried to "mro::set_mro("classname", "foo")" or "use mro
       'foo'", where "foo" is not a valid method resolution order (MRO).
       Currently, the only valid ones supported are "dfs" and "c3", unless
       you have loaded a module that is a MRO plugin.  See mro and
       perlmroapi.

   Invalid negative number (%s) in chr
       (W utf8) You passed a negative number to "chr".  Negative numbers
       are not valid character numbers, so it returns the Unicode
       replacement character (U+FFFD).

   Invalid number '%s' for -C option.
       (F) You supplied a number to the -C option that either has extra
       leading zeroes or overflows perl's unsigned integer representation.

   invalid option -D%c, use -D'' to see choices
       (S debugging) Perl was called with invalid debugger flags.  Call
       perl with the -D option with no flags to see the list of acceptable
       values.  See also "-Dletters" in perlrun.

   Invalid quantifier in {,} in regex; marked by <--HERE in m/%s/
       (F) The pattern looks like a {min,max} quantifier, but the min or
       max could not be parsed as a valid number - either it has leading
       zeroes, or it represents too big a number to cope with.  The
       <--HERE shows where in the regular expression the problem was
       discovered.  See perlre.

   Invalid [] range "%s" in regex; marked by <--HERE in m/%s/
       (F) The range specified in a character class had a minimum
       character greater than the maximum character.  One possibility is
       that you forgot the "{}" from your ending "\x{}" - "\x" without the
       curly braces can go only up to "ff".  The <--HERE shows
       whereabouts in the regular expression the problem was discovered.
       See perlre.

   Invalid range "%s" in transliteration operator
       (F) The range specified in the tr/// or y/// operator had a minimum
       character greater than the maximum character.  See perlop.

   Invalid separator character %s in attribute list
       (F) Something other than a colon or whitespace was seen between the
       elements of an attribute list.  If the previous attribute had a
       parenthesised parameter list, perhaps that list was terminated too
       soon.  See attributes.

   Invalid separator character %s in PerlIO layer specification %s
       (W layer) When pushing layers onto the Perl I/O system, something
       other than a colon or whitespace was seen between the elements of a
       layer list.  If the previous attribute had a parenthesised
       parameter list, perhaps that list was terminated too soon.

   Invalid strict version format (%s)
       (F) A version number did not meet the "strict" criteria for
       versions.  A "strict" version number is a positive decimal number
       (integer or decimal-fraction) without exponentiation or else a
       dotted-decimal v-string with a leading 'v' character and at least
       three components.  The parenthesized text indicates which criteria
       were not met.  See the version module for more details on allowed
       version formats.

   Invalid type '%s' in %s
       (F) The given character is not a valid pack or unpack type.  See
       "pack" in perlfunc.

       (W) The given character is not a valid pack or unpack type but used
       to be silently ignored.

   Invalid version format (%s)
       (F) A version number did not meet the "lax" criteria for versions.
       A "lax" version number is a positive decimal number (integer or
       decimal-fraction) without exponentiation or else a dotted-decimal
       v-string.  If the v-string has fewer than three components, it must
       have a leading 'v' character.  Otherwise, the leading 'v' is
       optional.  Both decimal and dotted-decimal versions may have a
       trailing "alpha" component separated by an underscore character
       after a fractional or dotted-decimal component.  The parenthesized
       text indicates which criteria were not met.  See the version module
       for more details on allowed version formats.

   Invalid version object
       (F) The internal structure of the version object was invalid.
       Perhaps the internals were modified directly in some way or an
       arbitrary reference was blessed into the "version" class.

   In '(*VERB...)', the '(' and '*' must be adjacent in regex; marked by
   <--HERE in m/%s/
       (F) The two-character sequence "(*" in this context in a regular
       expression pattern should be an indivisible token, with nothing
       intervening between the "(" and the "*", but you separated them.

   ioctl is not implemented
       (F) Your machine apparently doesn't implement ioctl(), which is
       pretty strange for a machine that supports C.

   ioctl() on unopened %s
       (W unopened) You tried ioctl() on a filehandle that was never
       opened.  Check your control flow and number of arguments.

   IO layers (like '%s') unavailable
       (F) Your Perl has not been configured to have PerlIO, and therefore
       you cannot use IO layers.  To have PerlIO, Perl must be configured
       with 'useperlio'.

   IO::Socket::atmark not implemented on this architecture
       (F) Your machine doesn't implement the sockatmark() functionality,
       neither as a system call nor an ioctl call (SIOCATMARK).

   '%s' is an unknown bound type in regex; marked by <--HERE in m/%s/
       (F) You used "	{...}" or "\B{...}" and the "..." is not known to
       Perl.  The current valid ones are given in "	{}, 	, \B{}, \B" in
       perlrebackslash.

   %s() is deprecated on :utf8 handles
       (W deprecated) The sysread(), recv(), syswrite() and send()
       operators are deprecated on handles that have the ":utf8" layer,
       either explicitly, or implicitly, eg., with the
       ":encoding(UTF-16LE)" layer.

       Both sysread() and recv() currently use only the ":utf8" flag for
       the stream, ignoring the actual layers.  Since sysread() and recv()
       do no UTF-8 validation they can end up creating invalidly encoded
       scalars.

       Similarly, syswrite() and send() use only the ":utf8" flag,
       otherwise ignoring any layers.  If the flag is set, both write the
       value UTF-8 encoded, even if the layer is some different encoding,
       such as the example above.

       Ideally, all of these operators would completely ignore the ":utf8"
       state, working only with bytes, but this would result in silently
       breaking existing code.  To avoid this a future version of perl
       will throw an exception when any of sysread(), recv(), syswrite()
       or send() are called on handle with the ":utf8" layer.

   "%s" is more clearly written simply as "%s" in regex; marked by
   <--HERE in m/%s/
       (W regexp) (only under "usere'strict'" or within "(?[...])")

       You specified a character that has the given plainer way of writing
       it, and which is also portable to platforms running with different
       character sets.

   $* is no longer supported
       (D deprecated, syntax) The special variable $*, deprecated in older
       perls, has been removed as of 5.10.0 and is no longer supported.
       In previous versions of perl the use of $* enabled or disabled
       multi-line matching within a string.

       Instead of using $* you should use the "/m" (and maybe "/s") regexp
       modifiers.  You can enable "/m" for a lexical scope (even a whole
       file) with "use re '/m'".  (In older versions: when $* was set to a
       true value then all regular expressions behaved as if they were
       written using "/m".)

   $# is no longer supported
       (D deprecated, syntax) The special variable $#, deprecated in older
       perls, has been removed as of 5.10.0 and is no longer supported.
       You should use the printf/sprintf functions instead.

   '%s' is not a code reference
       (W overload) The second (fourth, sixth, ...) argument of
       overload::constant needs to be a code reference.  Either an
       anonymous subroutine, or a reference to a subroutine.

   '%s' is not an overloadable type
       (W overload) You tried to overload a constant type the overload
       package is unaware of.

   -i used with no filenames on the command line, reading from STDIN
       (S inplace) The "-i" option was passed on the command line,
       indicating that the script is intended to edit files in place, but
       no files were given.  This is usually a mistake, since editing
       STDIN in place doesn't make sense, and can be confusing because it
       can make perl look like it is hanging when it is really just trying
       to read from STDIN.  You should either pass a filename to edit, or
       remove "-i" from the command line.  See perlrun for more details.

   Junk on end of regexp in regex m/%s/
       (P) The regular expression parser is confused.

   Label not found for "last %s"
       (F) You named a loop to break out of, but you're not currently in a
       loop of that name, not even if you count where you were called
       from.  See "last" in perlfunc.

   Label not found for "next %s"
       (F) You named a loop to continue, but you're not currently in a
       loop of that name, not even if you count where you were called
       from.  See "last" in perlfunc.

   Label not found for "redo %s"
       (F) You named a loop to restart, but you're not currently in a loop
       of that name, not even if you count where you were called from.
       See "last" in perlfunc.

   leaving effective %s failed
       (F) While under the "use filetest" pragma, switching the real and
       effective uids or gids failed.

   length/code after end of string in unpack
       (F) While unpacking, the string buffer was already used up when an
       unpack length/code combination tried to obtain more data.  This
       results in an undefined value for the length.  See "pack" in
       perlfunc.

   length() used on %s (did you mean "scalar(%s)"?)
       (W syntax) You used length() on either an array or a hash when you
       probably wanted a count of the items.

       Array size can be obtained by doing:

           scalar(@array);

       The number of items in a hash can be obtained by doing:

           scalar(keys %hash);

   Lexing code attempted to stuff non-Latin-1 character into Latin-1 input
       (F) An extension is attempting to insert text into the current
       parse (using lex_stuff_pvn or similar), but tried to insert a
       character that couldn't be part of the current input.  This is an
       inherent pitfall of the stuffing mechanism, and one of the reasons
       to avoid it.  Where it is necessary to stuff, stuffing only plain
       ASCII is recommended.

   Lexing code internal error (%s)
       (F) Lexing code supplied by an extension violated the lexer's API
       in a detectable way.

   listen() on closed socket %s
       (W closed) You tried to do a listen on a closed socket.  Did you
       forget to check the return value of your socket() call?  See
       "listen" in perlfunc.

   List form of piped open not implemented
       (F) On some platforms, notably Windows, the three-or-more-arguments
       form of "open" does not support pipes, such as "open($pipe, '|-',
       @args)".  Use the two-argument "open($pipe, '|prog arg1 arg2...')"
       form instead.

   %s: loadable library and perl binaries are mismatched (got handshake
   key %p, needed %p)
       (P) A dynamic loading library ".so" or ".dll" was being loaded into
       the process that was built against a different build of perl than
       the said library was compiled against.  Reinstalling the XS module
       will likely fix this error.

   Locale '%s' may not work well.%s
       (W locale) You are using the named locale, which is a non-UTF-8
       one, and which perl has determined is not fully compatible with
       what it can handle.  The second %s gives a reason.

       By far the most common reason is that the locale has characters in
       it that are represented by more than one byte.  The only such
       locales that Perl can handle are the UTF-8 locales.  Most likely
       the specified locale is a non-UTF-8 one for an East Asian language
       such as Chinese or Japanese.  If the locale is a superset of ASCII,
       the ASCII portion of it may work in Perl.

       Some essentially obsolete locales that aren't supersets of ASCII,
       mainly those in ISO 646 or other 7-bit locales, such as ASMO 449,
       can also have problems, depending on what portions of the ASCII
       character set get changed by the locale and are also used by the
       program.  The warning message lists the determinable conflicting
       characters.

       Note that not all incompatibilities are found.

       If this happens to you, there's not much you can do except switch
       to use a different locale or use Encode to translate from the
       locale into UTF-8; if that's impracticable, you have been warned
       that some things may break.

       This message is output once each time a bad locale is switched into
       within the scope of "uselocale", or on the first possibly-affected
       operation if the "uselocale" inherits a bad one.  It is not raised
       for any operations from the POSIX module.

   localtime(%f) failed
       (W overflow) You called "localtime" with a number that it could not
       handle: too large, too small, or NaN.  The returned value is
       "undef".

   localtime(%f) too large
       (W overflow) You called "localtime" with a number that was larger
       than it can reliably handle and "localtime" probably returned the
       wrong date.  This warning is also triggered with NaN (the special
       not-a-number value).

   localtime(%f) too small
       (W overflow) You called "localtime" with a number that was smaller
       than it can reliably handle and "localtime" probably returned the
       wrong date.

   Lookbehind longer than %d not implemented in regex m/%s/
       (F) There is currently a limit on the length of string which
       lookbehind can handle.  This restriction may be eased in a future
       release.

   Lost precision when %s %f by 1
       (W imprecision) The value you attempted to increment or decrement
       by one is too large for the underlying floating point
       representation to store accurately, hence the target of "++" or
       "--" is unchanged.  Perl issues this warning because it has already
       switched from integers to floating point when values are too large
       for integers, and now even floating point is insufficient.  You may
       wish to switch to using Math::BigInt explicitly.

   lstat() on filehandle%s
       (W io) You tried to do an lstat on a filehandle.  What did you mean
       by that?  lstat() makes sense only on filenames.  (Perl did a
       fstat() instead on the filehandle.)

   lvalue attribute %s already-defined subroutine
       (W misc) Although attributes.pm allows this, turning the lvalue
       attribute on or off on a Perl subroutine that is already defined
       does not always work properly.  It may or may not do what you want,
       depending on what code is inside the subroutine, with exact details
       subject to change between Perl versions.  Only do this if you
       really know what you are doing.

   lvalue attribute ignored after the subroutine has been defined
       (W misc) Using the ":lvalue" declarative syntax to make a Perl
       subroutine an lvalue subroutine after it has been defined is not
       permitted.  To make the subroutine an lvalue subroutine, add the
       lvalue attribute to the definition, or put the "sub foo :lvalue;"
       declaration before the definition.

       See also attributes.pm.

   Magical list constants are not supported
       (F) You assigned a magical array to a stash element, and then tried
       to use the subroutine from the same slot.  You are asking Perl to
       do something it cannot do, details subject to change between Perl
       versions.

   Malformed integer in [] in pack
       (F) Between the brackets enclosing a numeric repeat count only
       digits are permitted.  See "pack" in perlfunc.

   Malformed integer in [] in unpack
       (F) Between the brackets enclosing a numeric repeat count only
       digits are permitted.  See "pack" in perlfunc.

   Malformed PERLLIB_PREFIX
       (F) An error peculiar to OS/2.  PERLLIB_PREFIX should be of the
       form

           prefix1;prefix2

       or
           prefix1 prefix2

       with nonempty prefix1 and prefix2.  If "prefix1" is indeed a prefix
       of a builtin library search path, prefix2 is substituted.  The
       error may appear if components are not found, or are too long.  See
       "PERLLIB_PREFIX" in perlos2.

   Malformed prototype for %s: %s
       (F) You tried to use a function with a malformed prototype.  The
       syntax of function prototypes is given a brief compile-time check
       for obvious errors like invalid characters.  A more rigorous check
       is run when the function is called.  Perhaps the function's author
       was trying to write a subroutine signature but didn't enable that
       feature first ("use feature 'signatures'"), so the signature was
       instead interpreted as a bad prototype.

   Malformed UTF-8 character (%s)
       (S utf8)(F) Perl detected a string that didn't comply with UTF-8
       encoding rules, even though it had the UTF8 flag on.

       One possible cause is that you set the UTF8 flag yourself for data
       that you thought to be in UTF-8 but it wasn't (it was for example
       legacy 8-bit data).  To guard against this, you can use
       Encode::decode_utf8.

       If you use the ":encoding(UTF-8)" PerlIO layer for input, invalid
       byte sequences are handled gracefully, but if you use ":utf8", the
       flag is set without validating the data, possibly resulting in this
       error message.

       See also "Handling Malformed Data" in Encode.

   Malformed UTF-8 character immediately after '%s'
       (F) You said "use utf8", but the program file doesn't comply with
       UTF-8 encoding rules.  The message prints out the properly encoded
       characters just before the first bad one.  If "utf8" warnings are
       enabled, a warning is generated that gives more details about the
       type of malformation.

   Malformed UTF-8 returned by \N{%s} immediately after '%s'
       (F) The charnames handler returned malformed UTF-8.

   Malformed UTF-8 string in '%c' format in unpack
       (F) You tried to unpack something that didn't comply with UTF-8
       encoding rules and perl was unable to guess how to make more
       progress.

   Malformed UTF-8 string in pack
       (F) You tried to pack something that didn't comply with UTF-8
       encoding rules and perl was unable to guess how to make more
       progress.

   Malformed UTF-8 string in unpack
       (F) You tried to unpack something that didn't comply with UTF-8
       encoding rules and perl was unable to guess how to make more
       progress.

   Malformed UTF-16 surrogate
       (F) Perl thought it was reading UTF-16 encoded character data but
       while doing it Perl met a malformed Unicode surrogate.

   Mandatory parameter follows optional parameter
       (F) In a subroutine signature, you wrote something like "$a =
       undef, $b", making an earlier parameter optional and a later one
       mandatory.  Parameters are filled from left to right, so it's
       impossible for the caller to omit an earlier one and pass a later
       one.  If you want to act as if the parameters are filled from right
       to left, declare the rightmost optional and then shuffle the
       parameters around in the subroutine's body.

   Matched non-Unicode code point 0x%X against Unicode property; may not
   be portable
       (S non_unicode) Perl allows strings to contain a superset of
       Unicode code points; each code point may be as large as what is
       storable in an unsigned integer on your system, but these may not
       be accepted by other languages/systems.  This message occurs when
       you matched a string containing such a code point against a regular
       expression pattern, and the code point was matched against a
       Unicode property, "\p{...}" or "\P{...}".  Unicode properties are
       only defined on Unicode code points, so the result of this match is
       undefined by Unicode, but Perl (starting in v5.20) treats non-
       Unicode code points as if they were typical unassigned Unicode
       ones, and matched this one accordingly.  Whether a given property
       matches these code points or not is specified in "Properties
       accessible through \p{} and \P{}" in perluniprops.

       This message is suppressed (unless it has been made fatal) if it is
       immaterial to the results of the match if the code point is Unicode
       or not.  For example, the property "\p{ASCII_Hex_Digit}" only can
       match the 22 characters "[0-9A-Fa-f]", so obviously all other code
       points, Unicode or not, won't match it.  (And "\P{ASCII_Hex_Digit}"
       will match every code point except these 22.)

       Getting this message indicates that the outcome of the match
       arguably should have been the opposite of what actually happened.
       If you think that is the case, you may wish to make the
       "non_unicode" warnings category fatal; if you agree with Perl's
       decision, you may wish to turn off this category.

       See "Beyond Unicode code points" in perlunicode for more
       information.

   %s matches null string many times in regex; marked by <--HERE in m/%s/
       (W regexp) The pattern you've specified would be an infinite loop
       if the regular expression engine didn't specifically check for
       that.  The <--HERE shows whereabouts in the regular expression the
       problem was discovered.  See perlre.

   Maximal count of pending signals (%u) exceeded
       (F) Perl aborted due to too high a number of signals pending.  This
       usually indicates that your operating system tried to deliver
       signals too fast (with a very high priority), starving the perl
       process from resources it would need to reach a point where it can
       process signals safely.  (See "Deferred Signals (Safe Signals)" in
       perlipc.)

   "%s" may clash with future reserved word
       (W) This warning may be due to running a perl5 script through a
       perl4 interpreter, especially if the word that is being warned
       about is "use" or "my".

   '%' may not be used in pack
       (F) You can't pack a string by supplying a checksum, because the
       checksumming process loses information, and you can't go the other
       way.  See "unpack" in perlfunc.

   Method for operation %s not found in package %s during blessing
       (F) An attempt was made to specify an entry in an overloading table
       that doesn't resolve to a valid subroutine.  See overload.

   Method %s not permitted
       See Server error.

   Might be a runaway multi-line %s string starting on line %d
       (S) An advisory indicating that the previous error may have been
       caused by a missing delimiter on a string or pattern, because it
       eventually ended earlier on the current line.

   Misplaced _ in number
       (W syntax) An underscore (underbar) in a numeric constant did not
       separate two digits.

   Missing argument in %s
       (W missing) You called a function with fewer arguments than other
       arguments you supplied indicated would be needed.

       Currently only emitted when a printf-type format required more
       arguments than were supplied, but might be used in the future for
       other cases where we can statically determine that arguments to
       functions are missing, e.g. for the "pack" in perlfunc function.

   Missing argument to -%c
       (F) The argument to the indicated command line switch must follow
       immediately after the switch, without intervening spaces.

   Missing braces on \N{}
   Missing braces on \N{} in regex; marked by <--HERE in m/%s/
       (F) Wrong syntax of character name literal "\N{charname}" within
       double-quotish context.  This can also happen when there is a space
       (or comment) between the "\N" and the "{" in a regex with the "/x"
       modifier.  This modifier does not change the requirement that the
       brace immediately follow the "\N".

   Missing braces on \o{}
       (F) A "\o" must be followed immediately by a "{" in double-quotish
       context.

   Missing comma after first argument to %s function
       (F) While certain functions allow you to specify a filehandle or an
       "indirect object" before the argument list, this ain't one of them.

   Missing command in piped open
       (W pipe) You used the "open(FH, "| command")" or "open(FH, "command
       |")" construction, but the command was missing or blank.

   Missing control char name in \c
       (F) A double-quoted string ended with "\c", without the required
       control character name.

   Missing ']' in prototype for %s : %s
       (W illegalproto) A grouping was started with "[" but never closed
       with "]".

   Missing name in "%s sub"
       (F) The syntax for lexically scoped subroutines requires that they
       have a name with which they can be found.

   Missing $ on loop variable
       (F) Apparently you've been programming in csh too much.  Variables
       are always mentioned with the $ in Perl, unlike in the shells,
       where it can vary from one line to the next.

   (Missing operator before %s?)
       (S syntax) This is an educated guess made in conjunction with the
       message "%s found where operator expected".  Often the missing
       operator is a comma.

   Missing or undefined argument to require
       (F) You tried to call require with no argument or with an undefined
       value as an argument.  Require expects either a package name or a
       file-specification as an argument.  See "require" in perlfunc.

   Missing right brace on \%c{} in regex; marked by <--HERE in m/%s/
       (F) Missing right brace in "\x{...}", "\p{...}", "\P{...}", or
       "\N{...}".

   Missing right brace on \N{}
   Missing right brace on \N{} or unescaped left brace after \N
       (F) "\N" has two meanings.

       The traditional one has it followed by a name enclosed in braces,
       meaning the character (or sequence of characters) given by that
       name.  Thus "\N{ASTERISK}" is another way of writing "*", valid in
       both double-quoted strings and regular expression patterns.  In
       patterns, it doesn't have the meaning an unescaped "*" does.

       Starting in Perl 5.12.0, "\N" also can have an additional meaning
       (only) in patterns, namely to match a non-newline character.  (This
       is short for "[^\n]", and like "." but is not affected by the "/s"
       regex modifier.)

       This can lead to some ambiguities.  When "\N" is not followed
       immediately by a left brace, Perl assumes the "[^\n]" meaning.
       Also, if the braces form a valid quantifier such as "\N{3}" or
       "\N{5,}", Perl assumes that this means to match the given quantity
       of non-newlines (in these examples, 3; and 5 or more,
       respectively).  In all other case, where there is a "\N{" and a
       matching "}", Perl assumes that a character name is desired.

       However, if there is no matching "}", Perl doesn't know if it was
       mistakenly omitted, or if "[^\n]{" was desired, and raises this
       error.  If you meant the former, add the right brace; if you meant
       the latter, escape the brace with a backslash, like so: "\N\{"

   Missing right curly or square bracket
       (F) The lexer counted more opening curly or square brackets than
       closing ones.  As a general rule, you'll find it's missing near the
       place you were last editing.

   (Missing semicolon on previous line?)
       (S syntax) This is an educated guess made in conjunction with the
       message "%s found where operator expected".  Don't automatically
       put a semicolon on the previous line just because you saw this
       message.

   Modification of a read-only value attempted
       (F) You tried, directly or indirectly, to change the value of a
       constant.  You didn't, of course, try "2 = 1", because the compiler
       catches that.  But an easy way to do the same thing is:

           sub mod { $_[0] = 1 }
           mod(2);

       Another way is to assign to a substr() that's off the end of the
       string.

       Yet another way is to assign to a "foreach" loop VAR when VAR is
       aliased to a constant in the look LIST:

           $x = 1;
           foreach my $n ($x, 2) {
               $n *= 2; # modifies the $x, but fails on attempt to
           }            # modify the 2

   Modification of non-creatable array value attempted, %s
       (F) You tried to make an array value spring into existence, and the
       subscript was probably negative, even counting from end of the
       array backwards.

   Modification of non-creatable hash value attempted, %s
       (P) You tried to make a hash value spring into existence, and it
       couldn't be created for some peculiar reason.

   Module name must be constant
       (F) Only a bare module name is allowed as the first argument to a
       "use".

   Module name required with -%c option
       (F) The "-M" or "-m" options say that Perl should load some module,
       but you omitted the name of the module.  Consult perlrun for full
       details about "-M" and "-m".

   More than one argument to '%s' open
       (F) The "open" function has been asked to open multiple files.
       This can happen if you are trying to open a pipe to a command that
       takes a list of arguments, but have forgotten to specify a piped
       open mode.  See "open" in perlfunc for details.

   mprotect for COW string %p %u failed with %d
       (S) You compiled perl with -DPERL_DEBUG_READONLY_COW (see "Copy on
       Write" in perlguts), but a shared string buffer could not be made
       read-only.

   mprotect for %p %u failed with %d
       (S) You compiled perl with -DPERL_DEBUG_READONLY_OPS (see
       perlhacktips), but an op tree could not be made read-only.

   mprotect RW for COW string %p %u failed with %d
       (S) You compiled perl with -DPERL_DEBUG_READONLY_COW (see "Copy on
       Write" in perlguts), but a read-only shared string buffer could not
       be made mutable.

   mprotect RW for %p %u failed with %d
       (S) You compiled perl with -DPERL_DEBUG_READONLY_OPS (see
       perlhacktips), but a read-only op tree could not be made mutable
       before freeing the ops.

   msg%s not implemented
       (F) You don't have System V message IPC on your system.

   Multidimensional syntax %s not supported
       (W syntax) Multidimensional arrays aren't written like $foo[1,2,3].
       They're written like $foo[1][2][3], as in C.

   '/' must follow a numeric type in unpack
       (F) You had an unpack template that contained a '/', but this did
       not follow some unpack specification producing a numeric value.
       See "pack" in perlfunc.

   %s must not be a named sequence in transliteration operator
       (F) Transliteration ("tr///" and "y///") transliterates individual
       characters.  But a named sequence by definition is more than an
       individual charater, and hence doing this operation on it doesn't
       make sense.

   "my sub" not yet implemented
       (F) Lexically scoped subroutines are not yet implemented.  Don't
       try that yet.

   "my" subroutine %s can't be in a package
       (F) Lexically scoped subroutines aren't in a package, so it doesn't
       make sense to try to declare one with a package qualifier on the
       front.

   "my %s" used in sort comparison
       (W syntax) The package variables $a and $b are used for sort
       comparisons.  You used $a or $b in as an operand to the "<=>" or
       "cmp" operator inside a sort comparison block, and the variable had
       earlier been declared as a lexical variable.  Either qualify the
       sort variable with the package name, or rename the lexical
       variable.

   "my" variable %s can't be in a package
       (F) Lexically scoped variables aren't in a package, so it doesn't
       make sense to try to declare one with a package qualifier on the
       front.  Use local() if you want to localize a package variable.

   Name "%s::%s" used only once: possible typo
       (W once) Typographical errors often show up as unique variable
       names.  If you had a good reason for having a unique name, then
       just mention it again somehow to suppress the message.  The "our"
       declaration is also provided for this purpose.

       NOTE: This warning detects package symbols that have been used only
       once.  This means lexical variables will never trigger this
       warning.  It also means that all of the package variables $c, @c,
       %c, as well as *c, &c, sub c{}, c(), and c (the filehandle or
       format) are considered the same; if a program uses $c only once but
       also uses any of the others it will not trigger this warning.
       Symbols beginning with an underscore and symbols using special
       identifiers (q.v. perldata) are exempt from this warning.

   Need exactly 3 octal digits in regex; marked by <--HERE in m/%s/
       (F) Within "(?[])", all constants interpreted as octal need to
       be exactly 3 digits long.  This helps catch some ambiguities.  If
       your constant is too short, add leading zeros, like

        (?[ [ \078 ] ])     # Syntax error!
        (?[ [ \0078 ] ])    # Works
        (?[ [ \007 8 ] ])   # Clearer

       The maximum number this construct can express is "\777".  If you
       need a larger one, you need to use \o{} instead.  If you meant two
       separate things, you need to separate them:

        (?[ [ \7776 ] ])        # Syntax error!
        (?[ [ \o{7776} ] ])     # One meaning
        (?[ [ \777 6 ] ])       # Another meaning
        (?[ [ \777 \006 ] ])    # Still another

   Negative '/' count in unpack
       (F) The length count obtained from a length/code unpack operation
       was negative.  See "pack" in perlfunc.

   Negative length
       (F) You tried to do a read/write/send/recv operation with a buffer
       length that is less than 0.  This is difficult to imagine.

   Negative offset to vec in lvalue context
       (F) When "vec" is called in an lvalue context, the second argument
       must be greater than or equal to zero.

   Negative repeat count does nothing
       (W numeric) You tried to execute the "x" repetition operator fewer
       than 0 times, which doesn't make sense.

   Nested quantifiers in regex; marked by <--HERE in m/%s/
       (F) You can't quantify a quantifier without intervening
       parentheses.  So things like ** or +* or ?* are illegal.  The
       <--HERE shows whereabouts in the regular expression the problem
       was discovered.

       Note that the minimal matching quantifiers, "*?", "+?", and "??"
       appear to be nested quantifiers, but aren't.  See perlre.

   %s never introduced
       (S internal) The symbol in question was declared but somehow went
       out of scope before it could possibly have been used.

   next::method/next::can/maybe::next::method cannot find enclosing method
       (F) "next::method" needs to be called within the context of a real
       method in a real package, and it could not find such a context.
       See mro.

   \N in a character class must be a named character: \N{...} in regex;
   marked by <--HERE in m/%s/
       (F) The new (as of Perl 5.12) meaning of "\N" as "[^\n]" is not
       valid in a bracketed character class, for the same reason that "."
       in a character class loses its specialness: it matches almost
       everything, which is probably not what you want.

   \N{} in inverted character class or as a range end-point is restricted
   to one character in regex; marked by <-- HERE in m/%s/
       (F) Named Unicode character escapes ("\N{...}") may return a multi-
       character sequence.  Even though a character class is supposed to
       match just one character of input, perl will match the whole thing
       correctly, except when the class is inverted ("[^...]"), or the
       escape is the beginning or final end point of a range.  The
       mathematically logical behavior for what matches when inverting is
       very different from what people expect, so we have decided to
       forbid it.  Similarly unclear is what should be generated when the
       "\N{...}" is used as one of the end points of the range, such as in

        [\x{41}-\N{ARABIC SEQUENCE YEH WITH HAMZA ABOVE WITH AE}]

       What is meant here is unclear, as the "\N{...}" escape is a
       sequence of code points, so this is made an error.

   \N{NAME} must be resolved by the lexer in regex; marked by <--HERE in
   m/%s/
       (F) When compiling a regex pattern, an unresolved named character
       or sequence was encountered.  This can happen in any of several
       ways that bypass the lexer, such as using single-quotish context,
       or an extra backslash in double-quotish:

           $re = '\N{SPACE}';  # Wrong!
           $re = "\\N{SPACE}"; # Wrong!
           /$re/;

       Instead, use double-quotes with a single backslash:

           $re = "\N{SPACE}";  # ok
           /$re/;

       The lexer can be bypassed as well by creating the pattern from
       smaller components:

           $re = '\N';
           /${re}{SPACE}/;     # Wrong!

       It's not a good idea to split a construct in the middle like this,
       and it doesn't work here.  Instead use the solution above.

       Finally, the message also can happen under the "/x" regex modifier
       when the "\N" is separated by spaces from the "{", in which case,
       remove the spaces.

           /\N {SPACE}/x;      # Wrong!
           /\N{SPACE}/x;       # ok

   No %s allowed while running setuid
       (F) Certain operations are deemed to be too insecure for a setuid
       or setgid script to even be allowed to attempt.  Generally speaking
       there will be another way to do what you want that is, if not
       secure, at least securable.  See perlsec.

   NO-BREAK SPACE in a charnames alias definition is deprecated
       (D deprecated) You defined a character name which contained a no-
       break space character.  Change it to a regular space.  Usually
       these names are defined in the ":alias" import argument to "use
       charnames", but they could be defined by a translator installed
       into $^H{charnames}.  See "CUSTOM ALIASES" in charnames.

   No code specified for -%c
       (F) Perl's -e and -E command-line options require an argument.  If
       you want to run an empty program, pass the empty string as a
       separate argument or run a program consisting of a single 0 or 1:

           perl -e ""
           perl -e0
           perl -e1

   No comma allowed after %s
       (F) A list operator that has a filehandle or "indirect object" is
       not allowed to have a comma between that and the following
       arguments.  Otherwise it'd be just another one of the arguments.

       One possible cause for this is that you expected to have imported a
       constant to your name space with use or import while no such
       importing took place, it may for example be that your operating
       system does not support that particular constant.  Hopefully you
       did use an explicit import list for the constants you expect to
       see; please see "use" in perlfunc and "import" in perlfunc.  While
       an explicit import list would probably have caught this error
       earlier it naturally does not remedy the fact that your operating
       system still does not support that constant.  Maybe you have a typo
       in the constants of the symbol import list of use or import or in
       the constant name at the line where this error was triggered?

   No command into which to pipe on command line
       (F) An error peculiar to VMS.  Perl handles its own command line
       redirection, and found a '|' at the end of the command line, so it
       doesn't know where you want to pipe the output from this command.

   No DB::DB routine defined
       (F) The currently executing code was compiled with the -d switch,
       but for some reason the current debugger (e.g. perl5db.pl or a
       "Devel::" module) didn't define a routine to be called at the
       beginning of each statement.

   No dbm on this machine
       (P) This is counted as an internal error, because every machine
       should supply dbm nowadays, because Perl comes with SDBM.  See
       SDBM_File.

   No DB::sub routine defined
       (F) The currently executing code was compiled with the -d switch,
       but for some reason the current debugger (e.g. perl5db.pl or a
       "Devel::" module) didn't define a "DB::sub" routine to be called at
       the beginning of each ordinary subroutine call.

   No directory specified for -I
       (F) The -I command-line switch requires a directory name as part of
       the same argument.  Use -Ilib, for instance.  -I lib won't work.

   No error file after 2> or 2>> on command line
       (F) An error peculiar to VMS.  Perl handles its own command line
       redirection, and found a '2>' or a '2>>' on the command line, but
       can't find the name of the file to which to write data destined for
       stderr.

   No group ending character '%c' found in template
       (F) A pack or unpack template has an opening '(' or '[' without its
       matching counterpart.  See "pack" in perlfunc.

   No input file after < on command line
       (F) An error peculiar to VMS.  Perl handles its own command line
       redirection, and found a '<' on the command line, but can't find
       the name of the file from which to read data for stdin.

   No next::method '%s' found for %s
       (F) "next::method" found no further instances of this method name
       in the remaining packages of the MRO of this class.  If you don't
       want it throwing an exception, use "maybe::next::method" or
       "next::can".  See mro.

   Non-finite repeat count does nothing
       (W numeric) You tried to execute the "x" repetition operator "Inf"
       (or "-Inf") or "NaN" times, which doesn't make sense.

   Non-hex character in regex; marked by <--HERE in m/%s/
       (F) In a regular expression, there was a non-hexadecimal character
       where a hex one was expected, like

        (?[ [ \xDG ] ])
        (?[ [ \x{DEKA} ] ])

   Non-octal character in regex; marked by <--HERE in m/%s/
       (F) In a regular expression, there was a non-octal character where
       an octal one was expected, like

        (?[ [ \o{1278} ] ])

   Non-octal character '%c'.  Resolved as "%s"
       (W digit) In parsing an octal numeric constant, a character was
       unexpectedly encountered that isn't octal.  The resulting value is
       as indicated.

   "no" not allowed in expression
       (F) The "no" keyword is recognized and executed at compile time,
       and returns no useful value.  See perlmod.

   Non-string passed as bitmask
       (W misc) A number has been passed as a bitmask argument to
       select().  Use the vec() function to construct the file descriptor
       bitmasks for select.  See "select" in perlfunc.

   No output file after > on command line
       (F) An error peculiar to VMS.  Perl handles its own command line
       redirection, and found a lone '>' at the end of the command line,
       so it doesn't know where you wanted to redirect stdout.

   No output file after > or >> on command line
       (F) An error peculiar to VMS.  Perl handles its own command line
       redirection, and found a '>' or a '>>' on the command line, but
       can't find the name of the file to which to write data destined for
       stdout.

   No package name allowed for variable %s in "our"
       (F) Fully qualified variable names are not allowed in "our"
       declarations, because that doesn't make much sense under existing
       rules.  Such syntax is reserved for future extensions.

   No Perl script found in input
       (F) You called "perl -x", but no line was found in the file
       beginning with #! and containing the word "perl".

   No setregid available
       (F) Configure didn't find anything resembling the setregid() call
       for your system.

   No setreuid available
       (F) Configure didn't find anything resembling the setreuid() call
       for your system.

   No such class %s
       (F) You provided a class qualifier in a "my", "our" or "state"
       declaration, but this class doesn't exist at this point in your
       program.

   No such class field "%s" in variable %s of type %s
       (F) You tried to access a key from a hash through the indicated
       typed variable but that key is not allowed by the package of the
       same type.  The indicated package has restricted the set of allowed
       keys using the fields pragma.

   No such hook: %s
       (F) You specified a signal hook that was not recognized by Perl.
       Currently, Perl accepts "__DIE__" and "__WARN__" as valid signal
       hooks.

   No such pipe open
       (P) An error peculiar to VMS.  The internal routine my_pclose()
       tried to close a pipe which hadn't been opened.  This should have
       been caught earlier as an attempt to close an unopened filehandle.

   No such signal: SIG%s
       (W signal) You specified a signal name as a subscript to %SIG that
       was not recognized.  Say "kill -l" in your shell to see the valid
       signal names on your system.

   Not a CODE reference
       (F) Perl was trying to evaluate a reference to a code value (that
       is, a subroutine), but found a reference to something else instead.
       You can use the ref() function to find out what kind of ref it
       really was.  See also perlref.

   Not a GLOB reference
       (F) Perl was trying to evaluate a reference to a "typeglob" (that
       is, a symbol table entry that looks like *foo), but found a
       reference to something else instead.  You can use the ref()
       function to find out what kind of ref it really was.  See perlref.

   Not a HASH reference
       (F) Perl was trying to evaluate a reference to a hash value, but
       found a reference to something else instead.  You can use the ref()
       function to find out what kind of ref it really was.  See perlref.

   Not an ARRAY reference
       (F) Perl was trying to evaluate a reference to an array value, but
       found a reference to something else instead.  You can use the ref()
       function to find out what kind of ref it really was.  See perlref.

   Not an unblessed ARRAY reference
       (F) You passed a reference to a blessed array to "push", "shift" or
       another array function.  These only accept unblessed array
       references or arrays beginning explicitly with "@".

   Not a SCALAR reference
       (F) Perl was trying to evaluate a reference to a scalar value, but
       found a reference to something else instead.  You can use the ref()
       function to find out what kind of ref it really was.  See perlref.

   Not a subroutine reference
       (F) Perl was trying to evaluate a reference to a code value (that
       is, a subroutine), but found a reference to something else instead.
       You can use the ref() function to find out what kind of ref it
       really was.  See also perlref.

   Not a subroutine reference in overload table
       (F) An attempt was made to specify an entry in an overloading table
       that doesn't somehow point to a valid subroutine.  See overload.

   Not enough arguments for %s
       (F) The function requires more arguments than you specified.

   Not enough format arguments
       (W syntax) A format specified more picture fields than the next
       line supplied.  See perlform.

   %s: not found
       (A) You've accidentally run your script through the Bourne shell
       instead of Perl.  Check the #! line, or manually feed your script
       into Perl yourself.

   (?[...]) not valid in locale in regex; marked by <--HERE in m/%s/
       (F) "(?[...])" cannot be used within the scope of a "uselocale" or
       with an "/l" regular expression modifier, as that would require
       deferring to run-time the calculation of what it should evaluate
       to, and it is regex compile-time only.

   no UTC offset information; assuming local time is UTC
       (S) A warning peculiar to VMS.  Perl was unable to find the local
       timezone offset, so it's assuming that local system time is
       equivalent to UTC.  If it's not, define the logical name
       SYS$TIMEZONE_DIFFERENTIAL to translate to the number of seconds
       which need to be added to UTC to get local time.

   NULL OP IN RUN
       (S debugging) Some internal routine called run() with a null opcode
       pointer.

   Null picture in formline
       (F) The first argument to formline must be a valid format picture
       specification.  It was found to be empty, which probably means you
       supplied it an uninitialized value.  See perlform.

   Null realloc
       (P) An attempt was made to realloc NULL.

   NULL regexp argument
       (P) The internal pattern matching routines blew it big time.

   NULL regexp parameter
       (P) The internal pattern matching routines are out of their gourd.

   Number too long
       (F) Perl limits the representation of decimal numbers in programs
       to about 250 characters.  You've exceeded that length.  Future
       versions of Perl are likely to eliminate this arbitrary limitation.
       In the meantime, try using scientific notation (e.g. "1e6" instead
       of "1_000_000").

   Number with no digits
       (F) Perl was looking for a number but found nothing that looked
       like a number.  This happens, for example with "\o{}", with no
       number between the braces.

   Octal number > 037777777777 non-portable
       (W portable) The octal number you specified is larger than 2**32-1
       (4294967295) and therefore non-portable between systems.  See
       perlport for more on portability concerns.

   Odd name/value argument for subroutine
       (F) A subroutine using a slurpy hash parameter in its signature
       received an odd number of arguments to populate the hash.  It
       requires the arguments to be paired, with the same number of keys
       as values.  The caller of the subroutine is presumably at fault.
       Inconveniently, this error will be reported at the location of the
       subroutine, not that of the caller.

   Odd number of arguments for overload::constant
       (W overload) The call to overload::constant contained an odd number
       of arguments.  The arguments should come in pairs.

   Odd number of elements in anonymous hash
       (W misc) You specified an odd number of elements to initialize a
       hash, which is odd, because hashes come in key/value pairs.

   Odd number of elements in hash assignment
       (W misc) You specified an odd number of elements to initialize a
       hash, which is odd, because hashes come in key/value pairs.

   Offset outside string
       (F)(W layer) You tried to do a read/write/send/recv/seek operation
       with an offset pointing outside the buffer.  This is difficult to
       imagine.  The sole exceptions to this are that zero padding will
       take place when going past the end of the string when either
       "sysread()"ing a file, or when seeking past the end of a scalar
       opened for I/O (in anticipation of future reads and to imitate the
       behavior with real files).

   %s() on unopened %s
       (W unopened) An I/O operation was attempted on a filehandle that
       was never initialized.  You need to do an open(), a sysopen(), or a
       socket() call, or call a constructor from the FileHandle package.

   -%s on unopened filehandle %s
       (W unopened) You tried to invoke a file test operator on a
       filehandle that isn't open.  Check your control flow.  See also
       "-X" in perlfunc.

   oops: oopsAV
       (S internal) An internal warning that the grammar is screwed up.

   oops: oopsHV
       (S internal) An internal warning that the grammar is screwed up.

   Opening dirhandle %s also as a file
       (D io, deprecated) You used open() to associate a filehandle to a
       symbol (glob or scalar) that already holds a dirhandle.  Although
       legal, this idiom might render your code confusing and is
       deprecated.

   Opening filehandle %s also as a directory
       (D io, deprecated) You used opendir() to associate a dirhandle to a
       symbol (glob or scalar) that already holds a filehandle.  Although
       legal, this idiom might render your code confusing and is
       deprecated.

   Operand with no preceding operator in regex; marked by <--HERE in
   m/%s/
       (F) You wrote something like

        (?[ \p{Digit} \p{Thai} ])

       There are two operands, but no operator giving how you want to
       combine them.

   Operation "%s": no method found, %s
       (F) An attempt was made to perform an overloaded operation for
       which no handler was defined.  While some handlers can be
       autogenerated in terms of other handlers, there is no default
       handler for any operation, unless the "fallback" overloading key is
       specified to be true.  See overload.

   Operation "%s" returns its argument for non-Unicode code point 0x%X
       (S non_unicode) You performed an operation requiring Unicode rules
       on a code point that is not in Unicode, so what it should do is not
       defined.  Perl has chosen to have it do nothing, and warn you.

       If the operation shown is "ToFold", it means that case-insensitive
       matching in a regular expression was done on the code point.

       If you know what you are doing you can turn off this warning by "no
       warnings 'non_unicode';".

   Operation "%s" returns its argument for UTF-16 surrogate U+%X
       (S surrogate) You performed an operation requiring Unicode rules on
       a Unicode surrogate.  Unicode frowns upon the use of surrogates for
       anything but storing strings in UTF-16, but rules are (reluctantly)
       defined for the surrogates, and they are to do nothing for this
       operation.  Because the use of surrogates can be dangerous, Perl
       warns.

       If the operation shown is "ToFold", it means that case-insensitive
       matching in a regular expression was done on the code point.

       If you know what you are doing you can turn off this warning by "no
       warnings 'surrogate';".

   Operator or semicolon missing before %s
       (S ambiguous) You used a variable or subroutine call where the
       parser was expecting an operator.  The parser has assumed you
       really meant to use an operator, but this is highly likely to be
       incorrect.  For example, if you say "*foo *foo" it will be
       interpreted as if you said "*foo * 'foo'".

   Optional parameter lacks default expression
       (F) In a subroutine signature, you wrote something like "$a =",
       making a named optional parameter without a default value.  A
       nameless optional parameter is permitted to have no default value,
       but a named one must have a specific default.  You probably want
       "$a = undef".

   "our" variable %s redeclared
       (W misc) You seem to have already declared the same global once
       before in the current lexical scope.

   Out of memory!
       (X) The malloc() function returned 0, indicating there was
       insufficient remaining memory (or virtual memory) to satisfy the
       request.  Perl has no option but to exit immediately.

       At least in Unix you may be able to get past this by increasing
       your process datasize limits: in csh/tcsh use "limit" and "limit
       datasize n" (where "n" is the number of kilobytes) to check the
       current limits and change them, and in ksh/bash/zsh use "ulimit -a"
       and "ulimit -d n", respectively.

   Out of memory during %s extend
       (X) An attempt was made to extend an array, a list, or a string
       beyond the largest possible memory allocation.

   Out of memory during "large" request for %s
       (F) The malloc() function returned 0, indicating there was
       insufficient remaining memory (or virtual memory) to satisfy the
       request.  However, the request was judged large enough (compile-
       time default is 64K), so a possibility to shut down by trapping
       this error is granted.

   Out of memory during request for %s
       (X)(F) The malloc() function returned 0, indicating there was
       insufficient remaining memory (or virtual memory) to satisfy the
       request.

       The request was judged to be small, so the possibility to trap it
       depends on the way perl was compiled.  By default it is not
       trappable.  However, if compiled for this, Perl may use the
       contents of $^M as an emergency pool after die()ing with this
       message.  In this case the error is trappable once, and the error
       message will include the line and file where the failed request
       happened.

   Out of memory during ridiculously large request
       (F) You can't allocate more than 2^31+"small amount" bytes.  This
       error is most likely to be caused by a typo in the Perl program.
       e.g., $arr[time] instead of $arr[$time].

   Out of memory for yacc stack
       (F) The yacc parser wanted to grow its stack so it could continue
       parsing, but realloc() wouldn't give it more memory, virtual or
       otherwise.

   '.' outside of string in pack
       (F) The argument to a '.' in your template tried to move the
       working position to before the start of the packed string being
       built.

   '@' outside of string in unpack
       (F) You had a template that specified an absolute position outside
       the string being unpacked.  See "pack" in perlfunc.

   '@' outside of string with malformed UTF-8 in unpack
       (F) You had a template that specified an absolute position outside
       the string being unpacked.  The string being unpacked was also
       invalid UTF-8.  See "pack" in perlfunc.

   overload arg '%s' is invalid
       (W overload) The overload pragma was passed an argument it did not
       recognize.  Did you mistype an operator?

   Overloaded dereference did not return a reference
       (F) An object with an overloaded dereference operator was
       dereferenced, but the overloaded operation did not return a
       reference.  See overload.

   Overloaded qr did not return a REGEXP
       (F) An object with a "qr" overload was used as part of a match, but
       the overloaded operation didn't return a compiled regexp.  See
       overload.

   %s package attribute may clash with future reserved word: %s
       (W reserved) A lowercase attribute name was used that had a
       package-specific handler.  That name might have a meaning to Perl
       itself some day, even though it doesn't yet.  Perhaps you should
       use a mixed-case attribute name, instead.  See attributes.

   pack/unpack repeat count overflow
       (F) You can't specify a repeat count so large that it overflows
       your signed integers.  See "pack" in perlfunc.

   page overflow
       (W io) A single call to write() produced more lines than can fit on
       a page.  See perlform.

   panic: %s
       (P) An internal error.

   panic: attempt to call %s in %s
       (P) One of the file test operators entered a code branch that calls
       an ACL related-function, but that function is not available on this
       platform.  Earlier checks mean that it should not be possible to
       enter this branch on this platform.

   panic: child pseudo-process was never scheduled
       (P) A child pseudo-process in the ithreads implementation on
       Windows was not scheduled within the time period allowed and
       therefore was not able to initialize properly.

   panic: ck_grep, type=%u
       (P) Failed an internal consistency check trying to compile a grep.

   panic: ck_split, type=%u
       (P) Failed an internal consistency check trying to compile a split.

   panic: corrupt saved stack index %ld
       (P) The savestack was requested to restore more localized values
       than there are in the savestack.

   panic: del_backref
       (P) Failed an internal consistency check while trying to reset a
       weak reference.

   panic: do_subst
       (P) The internal pp_subst() routine was called with invalid
       operational data.

   panic: do_trans_%s
       (P) The internal do_trans routines were called with invalid
       operational data.

   panic: fold_constants JMPENV_PUSH returned %d
       (P) While attempting folding constants an exception other than an
       "eval" failure was caught.

   panic: frexp: %f
       (P) The library function frexp() failed, making printf("%f")
       impossible.

   panic: goto, type=%u, ix=%ld
       (P) We popped the context stack to a context with the specified
       label, and then discovered it wasn't a context we know how to do a
       goto in.

   panic: gp_free failed to free glob pointer
       (P) The internal routine used to clear a typeglob's entries tried
       repeatedly, but each time something re-created entries in the glob.
       Most likely the glob contains an object with a reference back to
       the glob and a destructor that adds a new object to the glob.

   panic: INTERPCASEMOD, %s
       (P) The lexer got into a bad state at a case modifier.

   panic: INTERPCONCAT, %s
       (P) The lexer got into a bad state parsing a string with brackets.

   panic: kid popen errno read
       (F) A forked child returned an incomprehensible message about its
       errno.

   panic: last, type=%u
       (P) We popped the context stack to a block context, and then
       discovered it wasn't a block context.

   panic: leave_scope clearsv
       (P) A writable lexical variable became read-only somehow within the
       scope.

   panic: leave_scope inconsistency %u
       (P) The savestack probably got out of sync.  At least, there was an
       invalid enum on the top of it.

   panic: magic_killbackrefs
       (P) Failed an internal consistency check while trying to reset all
       weak references to an object.

   panic: malloc, %s
       (P) Something requested a negative number of bytes of malloc.

   panic: memory wrap
       (P) Something tried to allocate either more memory than possible or
       a negative amount.

   panic: pad_alloc, %p!=%p
       (P) The compiler got confused about which scratch pad it was
       allocating and freeing temporaries and lexicals from.

   panic: pad_free curpad, %p!=%p
       (P) The compiler got confused about which scratch pad it was
       allocating and freeing temporaries and lexicals from.

   panic: pad_free po
       (P) A zero scratch pad offset was detected internally.  An attempt
       was made to free a target that had not been allocated to begin
       with.

   panic: pad_reset curpad, %p!=%p
       (P) The compiler got confused about which scratch pad it was
       allocating and freeing temporaries and lexicals from.

   panic: pad_sv po
       (P) A zero scratch pad offset was detected internally.  Most likely
       an operator needed a target but that target had not been allocated
       for whatever reason.

   panic: pad_swipe curpad, %p!=%p
       (P) The compiler got confused about which scratch pad it was
       allocating and freeing temporaries and lexicals from.

   panic: pad_swipe po
       (P) An invalid scratch pad offset was detected internally.

   panic: pp_iter, type=%u
       (P) The foreach iterator got called in a non-loop context frame.

   panic: pp_match%s
       (P) The internal pp_match() routine was called with invalid
       operational data.

   panic: pp_split, pm=%p, s=%p
       (P) Something terrible went wrong in setting up for the split.

   panic: realloc, %s
       (P) Something requested a negative number of bytes of realloc.

   panic: reference miscount on nsv in sv_replace() (%d != 1)
       (P) The internal sv_replace() function was handed a new SV with a
       reference count other than 1.

   panic: restartop in %s
       (P) Some internal routine requested a goto (or something like it),
       and didn't supply the destination.

   panic: return, type=%u
       (P) We popped the context stack to a subroutine or eval context,
       and then discovered it wasn't a subroutine or eval context.

   panic: scan_num, %s
       (P) scan_num() got called on something that wasn't a number.

   panic: Sequence (?{...}): no code block found in regex m/%s/
       (P) While compiling a pattern that has embedded (?{}) or (??{})
       code blocks, perl couldn't locate the code block that should have
       already been seen and compiled by perl before control passed to the
       regex compiler.

   panic: strxfrm() gets absurd - a => %u, ab => %u
       (P) The interpreter's sanity check of the C function strxfrm()
       failed.  In your current locale the returned transformation of the
       string "ab" is shorter than that of the string "a", which makes no
       sense.

   panic: sv_chop %s
       (P) The sv_chop() routine was passed a position that is not within
       the scalar's string buffer.

   panic: sv_insert, midend=%p, bigend=%p
       (P) The sv_insert() routine was told to remove more string than
       there was string.

   panic: top_env
       (P) The compiler attempted to do a goto, or something weird like
       that.

   panic: unimplemented op %s (#%d) called
       (P) The compiler is screwed up and attempted to use an op that
       isn't permitted at run time.

   panic: utf16_to_utf8: odd bytelen
       (P) Something tried to call utf16_to_utf8 with an odd (as opposed
       to even) byte length.

   panic: utf16_to_utf8_reversed: odd bytelen
       (P) Something tried to call utf16_to_utf8_reversed with an odd (as
       opposed to even) byte length.

   panic: yylex, %s
       (P) The lexer got into a bad state while processing a case
       modifier.

   Parentheses missing around "%s" list
       (W parenthesis) You said something like

           my $foo, $bar = @_;

       when you meant

           my ($foo, $bar) = @_;

       Remember that "my", "our", "local" and "state" bind tighter than
       comma.

   Parsing code internal error (%s)
       (F) Parsing code supplied by an extension violated the parser's API
       in a detectable way.

   Passing malformed UTF-8 to "%s" is deprecated
       (D deprecated, utf8) This message indicates a bug either in the
       Perl core or in XS code.  Such code was trying to find out if a
       character, allegedly stored internally encoded as UTF-8, was of a
       given type, such as being punctuation or a digit.  But the
       character was not encoded in legal UTF-8.  The %s is replaced by a
       string that can be used by knowledgeable people to determine what
       the type being checked against was.  If "utf8" warnings are
       enabled, a further message is raised, giving details of the
       malformation.

   Pattern subroutine nesting without pos change exceeded limit in regex
       (F) You used a pattern that uses too many nested subpattern calls
       without consuming any text.  Restructure the pattern so text is
       consumed before the nesting limit is exceeded.

   "-p" destination: %s
       (F) An error occurred during the implicit output invoked by the
       "-p" command-line switch.  (This output goes to STDOUT unless
       you've redirected it with select().)

   Perl API version %s of %s does not match %s
       (F) The XS module in question was compiled against a different
       incompatible version of Perl than the one that has loaded the XS
       module.

   Perl folding rules are not up-to-date for 0x%X; please use the perlbug
   utility to report; in regex; marked by <--HERE in m/%s/
       (S regexp) You used a regular expression with case-insensitive
       matching, and there is a bug in Perl in which the built-in regular
       expression folding rules are not accurate.  This may lead to
       incorrect results.  Please report this as a bug using the perlbug
       utility.

   PerlIO layer ':win32' is experimental
       (S experimental::win32_perlio) The ":win32" PerlIO layer is
       experimental.  If you want to take the risk of using this layer,
       simply disable this warning:

           no warnings "experimental::win32_perlio";

   Perl_my_%s() not available
       (F) Your platform has very uncommon byte-order and integer size, so
       it was not possible to set up some or all fixed-width byte-order
       conversion functions.  This is only a problem when you're using the
       '<' or '>' modifiers in (un)pack templates.  See "pack" in
       perlfunc.

   Perl %s required (did you mean %s?)--this is only %s, stopped
       (F) The code you are trying to run has asked for a newer version of
       Perl than you are running.  Perhaps "use 5.10" was written instead
       of "use 5.010" or "use v5.10".  Without the leading "v", the number
       is interpreted as a decimal, with every three digits after the
       decimal point representing a part of the version number.  So 5.10
       is equivalent to v5.100.

   Perl %s required--this is only %s, stopped
       (F) The module in question uses features of a version of Perl more
       recent than the currently running version.  How long has it been
       since you upgraded, anyway?  See "require" in perlfunc.

   PERL_SH_DIR too long
       (F) An error peculiar to OS/2.  PERL_SH_DIR is the directory to
       find the "sh"-shell in.  See "PERL_SH_DIR" in perlos2.

   PERL_SIGNALS illegal: "%s"
       (X) See "PERL_SIGNALS" in perlrun for legal values.

   Perls since %s too modern--this is %s, stopped
       (F) The code you are trying to run claims it will not run on the
       version of Perl you are using because it is too new.  Maybe the
       code needs to be updated, or maybe it is simply wrong and the
       version check should just be removed.

   perl: warning: Non hex character in '$ENV{PERL_HASH_SEED}', seed only
   partially set
       (S) PERL_HASH_SEED should match /^\s*(?:0x)?[0-9a-fA-F]+\s*\z/ but
       it contained a non hex character.  This could mean you are not
       using the hash seed you think you are.

   perl: warning: Setting locale failed.
       (S) The whole warning message will look something like:

               perl: warning: Setting locale failed.
               perl: warning: Please check that your locale settings:
                       LC_ALL = "En_US",
                       LANG = (unset)
                   are supported and installed on your system.
               perl: warning: Falling back to the standard locale ("C").

       Exactly what were the failed locale settings varies.  In the above
       the settings were that the LC_ALL was "En_US" and the LANG had no
       value.  This error means that Perl detected that you and/or your
       operating system supplier and/or system administrator have set up
       the so-called locale system but Perl could not use those settings.
       This was not dead serious, fortunately: there is a "default locale"
       called "C" that Perl can and will use, and the script will be run.
       Before you really fix the problem, however, you will get the same
       error message each time you run Perl.  How to really fix the
       problem can be found in perllocale section LOCALE PROBLEMS.

   perl: warning: strange setting in '$ENV{PERL_PERTURB_KEYS}': '%s'
       (S) Perl was run with the environment variable PERL_PERTURB_KEYS
       defined but containing an unexpected value.  The legal values of
       this setting are as follows.

         Numeric | String        | Result
         --------+---------------+-----------------------------------------
         0       | NO            | Disables key traversal randomization
         1       | RANDOM        | Enables full key traversal randomization
         2       | DETERMINISTIC | Enables repeatable key traversal
                 |               | randomization

       Both numeric and string values are accepted, but note that string
       values are case sensitive.  The default for this setting is
       "RANDOM" or 1.

   pid %x not a child
       (W exec) A warning peculiar to VMS.  Waitpid() was asked to wait
       for a process which isn't a subprocess of the current process.
       While this is fine from VMS' perspective, it's probably not what
       you intended.

   'P' must have an explicit size in unpack
       (F) The unpack format P must have an explicit size, not "*".

   POSIX class [:%s:] unknown in regex; marked by <--HERE in m/%s/
       (F) The class in the character class [: :] syntax is unknown.  The
       <--HERE shows whereabouts in the regular expression the problem
       was discovered.  Note that the POSIX character classes do not have
       the "is" prefix the corresponding C interfaces have: in other
       words, it's "[[:print:]]", not "isprint".  See perlre.

   POSIX getpgrp can't take an argument
       (F) Your system has POSIX getpgrp(), which takes no argument,
       unlike the BSD version, which takes a pid.

   POSIX syntax [%c %c] belongs inside character classes%s in regex;
   marked by <--HERE in m/%s/
       (W regexp) Perl thinks that you intended to write a POSIX character
       class, but didn't use enough brackets.  These POSIX class
       constructs [: :], [= =], and [. .]  go inside character classes,
       the [] are part of the construct, for example:
       "qr/[012[:alpha:]345]/".  What the regular expression pattern
       compiled to is probably not what you were intending.  For example,
       "qr/[:alpha:]/" compiles to a regular bracketed character class
       consisting of the four characters ":",  "a",  "l", "h", and "p".
       To specify the POSIX class, it should have been written
       "qr/[[:alpha:]]/".

       Note that [= =] and [. .] are not currently implemented; they are
       simply placeholders for future extensions and will cause fatal
       errors.  The <--HERE shows whereabouts in the regular expression
       the problem was discovered.  See perlre.

       If the specification of the class was not completely valid, the
       message indicates that.

   POSIX syntax [. .] is reserved for future extensions in regex; marked
   by <--HERE in m/%s/
       (F) Within regular expression character classes ([]) the syntax
       beginning with "[." and ending with ".]" is reserved for future
       extensions.  If you need to represent those character sequences
       inside a regular expression character class, just quote the square
       brackets with the backslash: "\[."  and ".\]".  The <--HERE shows
       whereabouts in the regular expression the problem was discovered.
       See perlre.

   POSIX syntax [= =] is reserved for future extensions in regex; marked
   by <--HERE in m/%s/
       (F) Within regular expression character classes ([]) the syntax
       beginning with "[=" and ending with "=]" is reserved for future
       extensions.  If you need to represent those character sequences
       inside a regular expression character class, just quote the square
       brackets with the backslash: "\[=" and "=\]".  The <--HERE shows
       whereabouts in the regular expression the problem was discovered.
       See perlre.

   Possible attempt to put comments in qw() list
       (W qw) qw() lists contain items separated by whitespace; as with
       literal strings, comment characters are not ignored, but are
       instead treated as literal data.  (You may have used different
       delimiters than the parentheses shown here; braces are also
       frequently used.)

       You probably wrote something like this:

           @list = qw(
               a # a comment
               b # another comment
           );

       when you should have written this:

           @list = qw(
               a
               b
           );

       If you really want comments, build your list the old-fashioned way,
       with quotes and commas:

           @list = (
               'a',    # a comment
               'b',    # another comment
           );

   Possible attempt to separate words with commas
       (W qw) qw() lists contain items separated by whitespace; therefore
       commas aren't needed to separate the items.  (You may have used
       different delimiters than the parentheses shown here; braces are
       also frequently used.)

       You probably wrote something like this:

           qw! a, b, c !;

       which puts literal commas into some of the list items.  Write it
       without commas if you don't want them to appear in your data:

           qw! a b c !;

   Possible memory corruption: %s overflowed 3rd argument
       (F) An ioctl() or fcntl() returned more than Perl was bargaining
       for.  Perl guesses a reasonable buffer size, but puts a sentinel
       byte at the end of the buffer just in case.  This sentinel byte got
       clobbered, and Perl assumes that memory is now corrupted.  See
       "ioctl" in perlfunc.

   Possible precedence issue with control flow operator
       (W syntax) There is a possible problem with the mixing of a control
       flow operator (e.g. "return") and a low-precedence operator like
       "or".  Consider:

           sub { return $a or $b; }

       This is parsed as:

           sub { (return $a) or $b; }

       Which is effectively just:

           sub { return $a; }

       Either use parentheses or the high-precedence variant of the
       operator.

       Note this may be also triggered for constructs like:

           sub { 1 if die; }

   Possible precedence problem on bitwise %s operator
       (W precedence) Your program uses a bitwise logical operator in
       conjunction with a numeric comparison operator, like this :

           if ($x & $y == 0) { ... }

       This expression is actually equivalent to "$x & ($y == 0)", due to
       the higher precedence of "==".  This is probably not what you want.
       (If you really meant to write this, disable the warning, or,
       better, put the parentheses explicitly and write "$x & ($y == 0)").

   Possible unintended interpolation of $\ in regex
       (W ambiguous) You said something like "m/$\/" in a regex.  The
       regex "m/foo$\s+bar/m" translates to: match the word 'foo', the
       output record separator (see "$\" in perlvar) and the letter 's'
       (one time or more) followed by the word 'bar'.

       If this is what you intended then you can silence the warning by
       using "m/${\}/" (for example: "m/foo${\}s+bar/").

       If instead you intended to match the word 'foo' at the end of the
       line followed by whitespace and the word 'bar' on the next line
       then you can use "m/$(?)\/" (for example: "m/foo$(?)\s+bar/").

   Possible unintended interpolation of %s in string
       (W ambiguous) You said something like '@foo' in a double-quoted
       string but there was no array @foo in scope at the time.  If you
       wanted a literal @foo, then write it as \@foo; otherwise find out
       what happened to the array you apparently lost track of.

   Precedence problem: open %s should be open(%s)
       (S precedence) The old irregular construct

           open FOO || die;

       is now misinterpreted as

           open(FOO || die);

       because of the strict regularization of Perl 5's grammar into unary
       and list operators.  (The old open was a little of both.)  You must
       put parentheses around the filehandle, or use the new "or" operator
       instead of "||".

   Premature end of script headers
       See Server error.

   printf() on closed filehandle %s
       (W closed) The filehandle you're writing to got itself closed
       sometime before now.  Check your control flow.

   print() on closed filehandle %s
       (W closed) The filehandle you're printing on got itself closed
       sometime before now.  Check your control flow.

   Process terminated by SIG%s
       (W) This is a standard message issued by OS/2 applications, while
       *nix applications die in silence.  It is considered a feature of
       the OS/2 port.  One can easily disable this by appropriate
       sighandlers, see "Signals" in perlipc.  See also "Process
       terminated by SIGTERM/SIGINT" in perlos2.

   Prototype after '%c' for %s : %s
       (W illegalproto) A character follows % or @ in a prototype.  This
       is useless, since % and @ gobble the rest of the subroutine
       arguments.

   Prototype mismatch: %s vs %s
       (S prototype) The subroutine being declared or defined had
       previously been declared or defined with a different function
       prototype.

   Prototype not terminated
       (F) You've omitted the closing parenthesis in a function prototype
       definition.

   Prototype '%s' overridden by attribute 'prototype(%s)' in %s
       (W prototype) A prototype was declared in both the parentheses
       after the sub name and via the prototype attribute.  The prototype
       in parentheses is useless, since it will be replaced by the
       prototype from the attribute before it's ever used.

   Quantifier follows nothing in regex; marked by <--HERE in m/%s/
       (F) You started a regular expression with a quantifier.  Backslash
       it if you meant it literally.  The <--HERE shows whereabouts in
       the regular expression the problem was discovered.  See perlre.

   Quantifier in {,} bigger than %d in regex; marked by <--HERE in m/%s/
       (F) There is currently a limit to the size of the min and max
       values of the {min,max} construct.  The <--HERE shows whereabouts
       in the regular expression the problem was discovered.  See perlre.

   Quantifier {n,m} with n > m can't match in regex
   Quantifier {n,m} with n > m can't match in regex; marked by <--HERE in
   m/%s/
       (W regexp) Minima should be less than or equal to maxima.  If you
       really want your regexp to match something 0 times, just put {0}.

   Quantifier unexpected on zero-length expression in regex m/%s/
       (W regexp) You applied a regular expression quantifier in a place
       where it makes no sense, such as on a zero-width assertion.  Try
       putting the quantifier inside the assertion instead.  For example,
       the way to match "abc" provided that it is followed by three
       repetitions of "xyz" is "/abc(?=(?:xyz){3})/", not
       "/abc(?=xyz){3}/".

   Range iterator outside integer range
       (F) One (or both) of the numeric arguments to the range operator
       ".."  are outside the range which can be represented by integers
       internally.  One possible workaround is to force Perl to use
       magical string increment by prepending "0" to your numbers.

   Ranges of ASCII printables should be some subset of "0-9", "A-Z", or
   "a-z" in regex; marked by <--HERE in m/%s/
       (W regexp) (only under "usere'strict'" or within "(?[...])")

       Stricter rules help to find typos and other errors.  Perhaps you
       didn't even intend a range here, if the "-" was meant to be some
       other character, or should have been escaped (like "\-").  If you
       did intend a range, the one that was used is not portable between
       ASCII and EBCDIC platforms, and doesn't have an obvious meaning to
       a casual reader.

        [3-7]    # OK; Obvious and portable
        [d-g]    # OK; Obvious and portable
        [A-Y]    # OK; Obvious and portable
        [A-z]    # WRONG; Not portable; not clear what is meant
        [a-Z]    # WRONG; Not portable; not clear what is meant
        [%-.]    # WRONG; Not portable; not clear what is meant
        [\x41-Z] # WRONG; Not portable; not obvious to non-geek

       (You can force portability by specifying a Unicode range, which
       means that the endpoints are specified by "\N{...}", but the
       meaning may still not be obvious.)  The stricter rules require that
       ranges that start or stop with an ASCII character that is not a
       control have all their endpoints be the literal character, and not
       some escape sequence (like "\x41"), and the ranges must be all
       digits, or all uppercase letters, or all lowercase letters.

   Ranges of digits should be from the same group in regex; marked by
   <--HERE in m/%s/
       (W regexp) (only under "usere'strict'" or within "(?[...])")

       Stricter rules help to find typos and other errors.  You included a
       range, and at least one of the end points is a decimal digit.
       Under the stricter rules, when this happens, both end points should
       be digits in the same group of 10 consecutive digits.

   readdir() attempted on invalid dirhandle %s
       (W io) The dirhandle you're reading from is either closed or not
       really a dirhandle.  Check your control flow.

   readline() on closed filehandle %s
       (W closed) The filehandle you're reading from got itself closed
       sometime before now.  Check your control flow.

   read() on closed filehandle %s
       (W closed) You tried to read from a closed filehandle.

   read() on unopened filehandle %s
       (W unopened) You tried to read from a filehandle that was never
       opened.

   Reallocation too large: %x
       (F) You can't allocate more than 64K on an MS-DOS machine.

   realloc() of freed memory ignored
       (S malloc) An internal routine called realloc() on something that
       had already been freed.

   Recompile perl with -DDEBUGGING to use -D switch
       (S debugging) You can't use the -D option unless the code to
       produce the desired output is compiled into Perl, which entails
       some overhead, which is why it's currently left out of your copy.

   Recursive call to Perl_load_module in PerlIO_find_layer
       (P) It is currently not permitted to load modules when creating a
       filehandle inside an %INC hook.  This can happen with "open my $fh,
       '<', \$scalar", which implicitly loads PerlIO::scalar.  Try loading
       PerlIO::scalar explicitly first.

   Recursive inheritance detected in package '%s'
       (F) While calculating the method resolution order (MRO) of a
       package, Perl believes it found an infinite loop in the @ISA
       hierarchy.  This is a crude check that bails out after 100 levels
       of @ISA depth.

   Redundant argument in %s
       (W redundant) You called a function with more arguments than other
       arguments you supplied indicated would be needed.  Currently only
       emitted when a printf-type format required fewer arguments than
       were supplied, but might be used in the future for e.g. "pack" in
       perlfunc.

   refcnt_dec: fd %d%s
   refcnt: fd %d%s
   refcnt_inc: fd %d%s
       (P) Perl's I/O implementation failed an internal consistency check.
       If you see this message, something is very wrong.

   Reference found where even-sized list expected
       (W misc) You gave a single reference where Perl was expecting a
       list with an even number of elements (for assignment to a hash).
       This usually means that you used the anon hash constructor when you
       meant to use parens.  In any case, a hash requires key/value pairs.

           %hash = { one => 1, two => 2, };    # WRONG
           %hash = [ qw/ an anon array / ];    # WRONG
           %hash = ( one => 1, two => 2, );    # right
           %hash = qw( one 1 two 2 );                  # also fine

   Reference is already weak
       (W misc) You have attempted to weaken a reference that is already
       weak.  Doing so has no effect.

   Reference to invalid group 0 in regex; marked by <--HERE in m/%s/
       (F) You used "\g0" or similar in a regular expression.  You may
       refer to capturing parentheses only with strictly positive integers
       (normal backreferences) or with strictly negative integers
       (relative backreferences).  Using 0 does not make sense.

   Reference to nonexistent group in regex; marked by <--HERE in m/%s/
       (F) You used something like "\7" in your regular expression, but
       there are not at least seven sets of capturing parentheses in the
       expression.  If you wanted to have the character with ordinal 7
       inserted into the regular expression, prepend zeroes to make it
       three digits long: "\007"

       The <--HERE shows whereabouts in the regular expression the
       problem was discovered.

   Reference to nonexistent named group in regex; marked by <--HERE in
   m/%s/
       (F) You used something like "\k'NAME'" or "\k<NAME>" in your
       regular expression, but there is no corresponding named capturing
       parentheses such as "(?'NAME'...)" or "(?<NAME>...)".  Check if the
       name has been spelled correctly both in the backreference and the
       declaration.

       The <--HERE shows whereabouts in the regular expression the
       problem was discovered.

   Reference to nonexistent or unclosed group in regex; marked by <--HERE
   in m/%s/
       (F) You used something like "\g{-7}" in your regular expression,
       but there are not at least seven sets of closed capturing
       parentheses in the expression before where the "\g{-7}" was
       located.

       The <--HERE shows whereabouts in the regular expression the
       problem was discovered.

   regexp memory corruption
       (P) The regular expression engine got confused by what the regular
       expression compiler gave it.

   Regexp modifier "/%c" may appear a maximum of twice
   Regexp modifier "%c" may appear a maximum of twice in regex; marked by
   <--HERE in m/%s/
       (F) The regular expression pattern had too many occurrences of the
       specified modifier.  Remove the extraneous ones.

   Regexp modifier "%c" may not appear after the "-" in regex; marked by
   <-- HERE in m/%s/
       (F) Turning off the given modifier has the side effect of turning
       on another one.  Perl currently doesn't allow this.  Reword the
       regular expression to use the modifier you want to turn on (and
       place it before the minus), instead of the one you want to turn
       off.

   Regexp modifier "/%c" may not appear twice
   Regexp modifier "%c" may not appear twice in regex; marked by <-- HERE
   in m/%s/
       (F) The regular expression pattern had too many occurrences of the
       specified modifier.  Remove the extraneous ones.

   Regexp modifiers "/%c" and "/%c" are mutually exclusive
   Regexp modifiers "%c" and "%c" are mutually exclusive in regex; marked
   by <--HERE in m/%s/
       (F) The regular expression pattern had more than one of these
       mutually exclusive modifiers.  Retain only the modifier that is
       supposed to be there.

   Regexp out of space in regex m/%s/
       (P) A "can't happen" error, because safemalloc() should have caught
       it earlier.

   Repeated format line will never terminate (~~ and @#)
       (F) Your format contains the ~~ repeat-until-blank sequence and a
       numeric field that will never go blank so that the repetition never
       terminates.  You might use ^# instead.  See perlform.

   Replacement list is longer than search list
       (W misc) You have used a replacement list that is longer than the
       search list.  So the additional elements in the replacement list
       are meaningless.

   '%s' resolved to '\o{%s}%d'
       (W misc, regexp)  You wrote something like "\08", or "\179" in a
       double-quotish string.  All but the last digit is treated as a
       single character, specified in octal.  The last digit is the next
       character in the string.  To tell Perl that this is indeed what you
       want, you can use the "\o{ }" syntax, or use exactly three digits
       to specify the octal for the character.

   Reversed %s= operator
       (W syntax) You wrote your assignment operator backwards.  The =
       must always come last, to avoid ambiguity with subsequent unary
       operators.

   rewinddir() attempted on invalid dirhandle %s
       (W io) The dirhandle you tried to do a rewinddir() on is either
       closed or not really a dirhandle.  Check your control flow.

   Scalars leaked: %d
       (S internal) Something went wrong in Perl's internal bookkeeping of
       scalars: not all scalar variables were deallocated by the time Perl
       exited.  What this usually indicates is a memory leak, which is of
       course bad, especially if the Perl program is intended to be long-
       running.

   Scalar value @%s[%s] better written as $%s[%s]
       (W syntax) You've used an array slice (indicated by @) to select a
       single element of an array.  Generally it's better to ask for a
       scalar value (indicated by $).  The difference is that $foo[&bar]
       always behaves like a scalar, both when assigning to it and when
       evaluating its argument, while @foo[&bar] behaves like a list when
       you assign to it, and provides a list context to its subscript,
       which can do weird things if you're expecting only one subscript.

       On the other hand, if you were actually hoping to treat the array
       element as a list, you need to look into how references work,
       because Perl will not magically convert between scalars and lists
       for you.  See perlref.

   Scalar value @%s{%s} better written as $%s{%s}
       (W syntax) You've used a hash slice (indicated by @) to select a
       single element of a hash.  Generally it's better to ask for a
       scalar value (indicated by $).  The difference is that $foo{&bar}
       always behaves like a scalar, both when assigning to it and when
       evaluating its argument, while @foo{&bar} behaves like a list when
       you assign to it, and provides a list context to its subscript,
       which can do weird things if you're expecting only one subscript.

       On the other hand, if you were actually hoping to treat the hash
       element as a list, you need to look into how references work,
       because Perl will not magically convert between scalars and lists
       for you.  See perlref.

   Search pattern not terminated
       (F) The lexer couldn't find the final delimiter of a // or m{}
       construct.  Remember that bracketing delimiters count nesting
       level.  Missing the leading "$" from a variable $m may cause this
       error.

       Note that since Perl 5.10.0 a // can also be the defined-or
       construct, not just the empty search pattern.  Therefore code
       written in Perl 5.10.0 or later that uses the // as the defined-or
       can be misparsed by pre-5.10.0 Perls as a non-terminated search
       pattern.

   seekdir() attempted on invalid dirhandle %s
       (W io) The dirhandle you are doing a seekdir() on is either closed
       or not really a dirhandle.  Check your control flow.

   %sseek() on unopened filehandle
       (W unopened) You tried to use the seek() or sysseek() function on a
       filehandle that was either never opened or has since been closed.

   select not implemented
       (F) This machine doesn't implement the select() system call.

   Self-ties of arrays and hashes are not supported
       (F) Self-ties are of arrays and hashes are not supported in the
       current implementation.

   Semicolon seems to be missing
       (W semicolon) A nearby syntax error was probably caused by a
       missing semicolon, or possibly some other missing operator, such as
       a comma.

   semi-panic: attempt to dup freed string
       (S internal) The internal newSVsv() routine was called to duplicate
       a scalar that had previously been marked as free.

   sem%s not implemented
       (F) You don't have System V semaphore IPC on your system.

   send() on closed socket %s
       (W closed) The socket you're sending to got itself closed sometime
       before now.  Check your control flow.

   Sequence "\c{" invalid
       (F) These three characters may not appear in sequence in a double-
       quotish context.  This message is raised only on non-ASCII
       platforms (a different error message is output on ASCII ones).  If
       you were intending to specify a control character with this
       sequence, you'll have to use a different way to specify it.

   Sequence (? incomplete in regex; marked by <--HERE in m/%s/
       (F) A regular expression ended with an incomplete extension (?.
       The <--HERE shows whereabouts in the regular expression the
       problem was discovered.  See perlre.

   Sequence (?%c...) not implemented in regex; marked by <--HERE in m/%s/
       (F) A proposed regular expression extension has the character
       reserved but has not yet been written.  The <--HERE shows
       whereabouts in the regular expression the problem was discovered.
       See perlre.

   Sequence (?%s...) not recognized in regex; marked by <--HERE in m/%s/
       (F) You used a regular expression extension that doesn't make
       sense.  The <--HERE shows whereabouts in the regular expression
       the problem was discovered.  This may happen when using the
       "(?^...)" construct to tell Perl to use the default regular
       expression modifiers, and you redundantly specify a default
       modifier.  For other causes, see perlre.

   Sequence (?#... not terminated in regex m/%s/
       (F) A regular expression comment must be terminated by a closing
       parenthesis.  Embedded parentheses aren't allowed.  See perlre.

   Sequence (?&... not terminated in regex; marked by <--HERE in m/%s/
       (F) A named reference of the form "(?&...)" was missing the final
       closing parenthesis after the name.  The <--HERE shows whereabouts
       in the regular expression the problem was discovered.

   Sequence (?%c... not terminated in regex; marked by <--HERE in m/%s/
       (F) A named group of the form "(?'...')" or "(?<...>)" was missing
       the final closing quote or angle bracket.  The <--HERE shows
       whereabouts in the regular expression the problem was discovered.

   Sequence (?(%c... not terminated in regex; marked by <--HERE in m/%s/
       (F) A named reference of the form "(?('...')...)" or
       "(?(<...>)...)" was missing the final closing quote or angle
       bracket after the name.  The <--HERE shows whereabouts in the
       regular expression the problem was discovered.

   Sequence (?... not terminated in regex; marked by <--HERE in m/%s/
       (F) There was no matching closing parenthesis for the '('.  The
       <--HERE shows whereabouts in the regular expression the problem
       was discovered.

   Sequence \%s... not terminated in regex; marked by <--HERE in m/%s/
       (F) The regular expression expects a mandatory argument following
       the escape sequence and this has been omitted or incorrectly
       written.

   Sequence (?{...}) not terminated with ')'
       (F) The end of the perl code contained within the {...} must be
       followed immediately by a ')'.

   Sequence (?P>... not terminated in regex; marked by <--HERE in m/%s/
       (F) A named reference of the form "(?P>...)" was missing the final
       closing parenthesis after the name.  The <--HERE shows whereabouts
       in the regular expression the problem was discovered.

   Sequence (?P<... not terminated in regex; marked by <--HERE in m/%s/
       (F) A named group of the form "(?P<...>')" was missing the final
       closing angle bracket.  The <--HERE shows whereabouts in the
       regular expression the problem was discovered.

   Sequence ?P=... not terminated in regex; marked by <--HERE in m/%s/
       (F) A named reference of the form "(?P=...)" was missing the final
       closing parenthesis after the name.  The <--HERE shows whereabouts
       in the regular expression the problem was discovered.

   Sequence (?R) not terminated in regex m/%s/
       (F) An "(?R)" or "(?0)" sequence in a regular expression was
       missing the final parenthesis.

   Server error (a.k.a. "500 Server error")
       (A) This is the error message generally seen in a browser window
       when trying to run a CGI program (including SSI) over the web.  The
       actual error text varies widely from server to server.  The most
       frequently-seen variants are "500 Server error", "Method
       (something) not permitted", "Document contains no data", "Premature
       end of script headers", and "Did not produce a valid header".

       This is a CGI error, not a Perl error.

       You need to make sure your script is executable, is accessible by
       the user CGI is running the script under (which is probably not the
       user account you tested it under), does not rely on any environment
       variables (like PATH) from the user it isn't running under, and
       isn't in a location where the CGI server can't find it, basically,
       more or less.  Please see the following for more information:

               http://www.perl.org/CGI_MetaFAQ.html
               http://www.htmlhelp.org/faq/cgifaq.html
               http://www.w3.org/Security/Faq/

       You should also look at perlfaq9.

   setegid() not implemented
       (F) You tried to assign to $), and your operating system doesn't
       support the setegid() system call (or equivalent), or at least
       Configure didn't think so.

   seteuid() not implemented
       (F) You tried to assign to $>, and your operating system doesn't
       support the seteuid() system call (or equivalent), or at least
       Configure didn't think so.

   setpgrp can't take arguments
       (F) Your system has the setpgrp() from BSD 4.2, which takes no
       arguments, unlike POSIX setpgid(), which takes a process ID and
       process group ID.

   setrgid() not implemented
       (F) You tried to assign to $(, and your operating system doesn't
       support the setrgid() system call (or equivalent), or at least
       Configure didn't think so.

   setruid() not implemented
       (F) You tried to assign to $<, and your operating system doesn't
       support the setruid() system call (or equivalent), or at least
       Configure didn't think so.

   setsockopt() on closed socket %s
       (W closed) You tried to set a socket option on a closed socket.
       Did you forget to check the return value of your socket() call?
       See "setsockopt" in perlfunc.

   Setting ${^ENCODING} is deprecated
       (D deprecated) You assigned a non-"undef" value to "${^ENCODING}".
       This is deprecated; see ""${^ENCODING}" in perlvar" for details.

   Setting $/ to a reference to %s as a form of slurp is deprecated,
   treating as undef
       (D deprecated) You assigned a reference to a scalar to $/ where the
       referenced item is not a positive integer.  In older perls this
       appeared to work the same as setting it to "undef" but was in fact
       internally different, less efficient and with very bad luck could
       have resulted in your file being split by a stringified form of the
       reference.

       In Perl 5.20.0 this was changed so that it would be exactly the
       same as setting $/ to undef, with the exception that this warning
       would be thrown.

       You are recommended to change your code to set $/ to "undef"
       explicitly if you wish to slurp the file. In future versions of
       Perl assigning a reference to will throw a fatal error.

   Setting $/ to %s reference is forbidden
       (F) You tried to assign a reference to a non integer to $/.  In
       older Perls this would have behaved similarly to setting it to a
       reference to a positive integer, where the integer was the address
       of the reference.  As of Perl 5.20.0 this is a fatal error, to
       allow future versions of Perl to use non-integer refs for more
       interesting purposes.

   shm%s not implemented
       (F) You don't have System V shared memory IPC on your system.

   !=~ should be !~
       (W syntax) The non-matching operator is !~, not !=~.  !=~ will be
       interpreted as the != (numeric not equal) and ~ (1's complement)
       operators: probably not what you intended.

   /%s/ should probably be written as "%s"
       (W syntax) You have used a pattern where Perl expected to find a
       string, as in the first argument to "join".  Perl will treat the
       true or false result of matching the pattern against $_ as the
       string, which is probably not what you had in mind.

   shutdown() on closed socket %s
       (W closed) You tried to do a shutdown on a closed socket.  Seems a
       bit superfluous.

   SIG%s handler "%s" not defined
       (W signal) The signal handler named in %SIG doesn't, in fact,
       exist.  Perhaps you put it into the wrong package?

   Slab leaked from cv %p
       (S) If you see this message, then something is seriously wrong with
       the internal bookkeeping of op trees.  An op tree needed to be
       freed after a compilation error, but could not be found, so it was
       leaked instead.

   sleep(%u) too large
       (W overflow) You called "sleep" with a number that was larger than
       it can reliably handle and "sleep" probably slept for less time
       than requested.

   Slurpy parameter not last
       (F) In a subroutine signature, you put something after a slurpy
       (array or hash) parameter.  The slurpy parameter takes all the
       available arguments, so there can't be any left to fill later
       parameters.

   Smart matching a non-overloaded object breaks encapsulation
       (F) You should not use the "~~" operator on an object that does not
       overload it: Perl refuses to use the object's underlying structure
       for the smart match.

   Smartmatch is experimental
       (S experimental::smartmatch) This warning is emitted if you use the
       smartmatch ("~~") operator.  This is currently an experimental
       feature, and its details are subject to change in future releases
       of Perl.  Particularly, its current behavior is noticed for being
       unnecessarily complex and unintuitive, and is very likely to be
       overhauled.

   sort is now a reserved word
       (F) An ancient error message that almost nobody ever runs into
       anymore.  But before sort was a keyword, people sometimes used it
       as a filehandle.

   Source filters apply only to byte streams
       (F) You tried to activate a source filter (usually by loading a
       source filter module) within a string passed to "eval".  This is
       not permitted under the "unicode_eval" feature.  Consider using
       "evalbytes" instead.  See feature.

   splice() offset past end of array
       (W misc) You attempted to specify an offset that was past the end
       of the array passed to splice().  Splicing will instead commence at
       the end of the array, rather than past it.  If this isn't what you
       want, try explicitly pre-extending the array by assigning $#array =
       $offset.  See "splice" in perlfunc.

   Split loop
       (P) The split was looping infinitely.  (Obviously, a split
       shouldn't iterate more times than there are characters of input,
       which is what happened.)  See "split" in perlfunc.

   Statement unlikely to be reached
       (W exec) You did an exec() with some statement after it other than
       a die().  This is almost always an error, because exec() never
       returns unless there was a failure.  You probably wanted to use
       system() instead, which does return.  To suppress this warning, put
       the exec() in a block by itself.

   "state" subroutine %s can't be in a package
       (F) Lexically scoped subroutines aren't in a package, so it doesn't
       make sense to try to declare one with a package qualifier on the
       front.

   "state %s" used in sort comparison
       (W syntax) The package variables $a and $b are used for sort
       comparisons.  You used $a or $b in as an operand to the "<=>" or
       "cmp" operator inside a sort comparison block, and the variable had
       earlier been declared as a lexical variable.  Either qualify the
       sort variable with the package name, or rename the lexical
       variable.

   "state" variable %s can't be in a package
       (F) Lexically scoped variables aren't in a package, so it doesn't
       make sense to try to declare one with a package qualifier on the
       front.  Use local() if you want to localize a package variable.

   stat() on unopened filehandle %s
       (W unopened) You tried to use the stat() function on a filehandle
       that was either never opened or has since been closed.

   Strings with code points over 0xFF may not be mapped into in-memory
   file handles
       (W utf8) You tried to open a reference to a scalar for read or
       append where the scalar contained code points over 0xFF.  In-memory
       files model on-disk files and can only contain bytes.

   Stub found while resolving method "%s" overloading "%s" in package "%s"
       (P) Overloading resolution over @ISA tree may be broken by
       importation stubs.  Stubs should never be implicitly created, but
       explicit calls to "can" may break this.

   Subroutine "&%s" is not available
       (W closure) During compilation, an inner named subroutine or eval
       is attempting to capture an outer lexical subroutine that is not
       currently available.  This can happen for one of two reasons.
       First, the lexical subroutine may be declared in an outer anonymous
       subroutine that has not yet been created.  (Remember that named
       subs are created at compile time, while anonymous subs are created
       at run-time.)  For example,

           sub { my sub a {...} sub f { \&a } }

       At the time that f is created, it can't capture the current "a"
       sub, since the anonymous subroutine hasn't been created yet.
       Conversely, the following won't give a warning since the anonymous
       subroutine has by now been created and is live:

           sub { my sub a {...} eval 'sub f { \&a }' }->();

       The second situation is caused by an eval accessing a lexical
       subroutine that has gone out of scope, for example,

           sub f {
               my sub a {...}
               sub { eval '\&a' }
           }
           f()->();

       Here, when the '\&a' in the eval is being compiled, f() is not
       currently being executed, so its &a is not available for capture.

   "%s" subroutine &%s masks earlier declaration in same %s
       (W misc) A "my" or "state" subroutine has been redeclared in the
       current scope or statement, effectively eliminating all access to
       the previous instance.  This is almost always a typographical
       error.  Note that the earlier subroutine will still exist until the
       end of the scope or until all closure references to it are
       destroyed.

   Subroutine %s redefined
       (W redefine) You redefined a subroutine.  To suppress this warning,
       say

           {
               no warnings 'redefine';
               eval "sub name { ... }";
           }

   Subroutine "%s" will not stay shared
       (W closure) An inner (nested) named subroutine is referencing a
       "my" subroutine defined in an outer named subroutine.

       When the inner subroutine is called, it will see the value of the
       outer subroutine's lexical subroutine as it was before and during
       the *first* call to the outer subroutine; in this case, after the
       first call to the outer subroutine is complete, the inner and outer
       subroutines will no longer share a common value for the lexical
       subroutine.  In other words, it will no longer be shared.  This
       will especially make a difference if the lexical subroutines
       accesses lexical variables declared in its surrounding scope.

       This problem can usually be solved by making the inner subroutine
       anonymous, using the "sub {}" syntax.  When inner anonymous subs
       that reference lexical subroutines in outer subroutines are
       created, they are automatically rebound to the current values of
       such lexical subs.

   Substitution loop
       (P) The substitution was looping infinitely.  (Obviously, a
       substitution shouldn't iterate more times than there are characters
       of input, which is what happened.)  See the discussion of
       substitution in "Regexp Quote-Like Operators" in perlop.

   Substitution pattern not terminated
       (F) The lexer couldn't find the interior delimiter of an s/// or
       s{}{} construct.  Remember that bracketing delimiters count nesting
       level.  Missing the leading "$" from variable $s may cause this
       error.

   Substitution replacement not terminated
       (F) The lexer couldn't find the final delimiter of an s/// or s{}{}
       construct.  Remember that bracketing delimiters count nesting
       level.  Missing the leading "$" from variable $s may cause this
       error.

   substr outside of string
       (W substr)(F) You tried to reference a substr() that pointed
       outside of a string.  That is, the absolute value of the offset was
       larger than the length of the string.  See "substr" in perlfunc.
       This warning is fatal if substr is used in an lvalue context (as
       the left hand side of an assignment or as a subroutine argument for
       example).

   sv_upgrade from type %d down to type %d
       (P) Perl tried to force the upgrade of an SV to a type which was
       actually inferior to its current type.

   SWASHNEW didn't return an HV ref
       (P) Something went wrong internally when Perl was trying to look up
       Unicode characters.

   Switch (?(condition)... contains too many branches in regex; marked by
   <--HERE in m/%s/
       (F) A (?(condition)if-clause|else-clause) construct can have at
       most two branches (the if-clause and the else-clause).  If you want
       one or both to contain alternation, such as using
       "this|that|other", enclose it in clustering parentheses:

           (?(condition)(?:this|that|other)|else-clause)

       The <--HERE shows whereabouts in the regular expression the
       problem was discovered.  See perlre.

   Switch condition not recognized in regex; marked by <--HERE in m/%s/
       (F) The condition part of a (?(condition)if-clause|else-clause)
       construct is not known.  The condition must be one of the
       following:

        (1) (2) ...        true if 1st, 2nd, etc., capture matched
        (<NAME>) ('NAME')  true if named capture matched
        (?=...) (?<=...)   true if subpattern matches
        (?!...) (?<!...)   true if subpattern fails to match
        (?{ CODE })        true if code returns a true value
        (R)                true if evaluating inside recursion
        (R1) (R2) ...      true if directly inside capture group 1, 2, etc.
        (R&NAME)           true if directly inside named capture
        (DEFINE)           always false; for defining named subpatterns

       The <--HERE shows whereabouts in the regular expression the
       problem was discovered.  See perlre.

   Switch (?(condition)... not terminated in regex; marked by <--HERE in
   m/%s/
       (F) You omitted to close a (?(condition)...) block somewhere in the
       pattern.  Add a closing parenthesis in the appropriate position.
       See perlre.

   switching effective %s is not implemented
       (F) While under the "use filetest" pragma, we cannot switch the
       real and effective uids or gids.

   syntax error
       (F) Probably means you had a syntax error.  Common reasons include:

           A keyword is misspelled.
           A semicolon is missing.
           A comma is missing.
           An opening or closing parenthesis is missing.
           An opening or closing brace is missing.
           A closing quote is missing.

       Often there will be another error message associated with the
       syntax error giving more information.  (Sometimes it helps to turn
       on -w.)  The error message itself often tells you where it was in
       the line when it decided to give up.  Sometimes the actual error is
       several tokens before this, because Perl is good at understanding
       random input.  Occasionally the line number may be misleading, and
       once in a blue moon the only way to figure out what's triggering
       the error is to call "perl -c" repeatedly, chopping away half the
       program each time to see if the error went away.  Sort of the
       cybernetic version of 20questions.

   syntax error at line %d: '%s' unexpected
       (A) You've accidentally run your script through the Bourne shell
       instead of Perl.  Check the #! line, or manually feed your script
       into Perl yourself.

   syntax error in file %s at line %d, next 2 tokens "%s"
       (F) This error is likely to occur if you run a perl5 script through
       a perl4 interpreter, especially if the next 2 tokens are "use
       strict" or "my $var" or "our $var".

   Syntax error in (?[...]) in regex m/%s/
       (F) Perl could not figure out what you meant inside this construct;
       this notifies you that it is giving up trying.

   %s syntax OK
       (F) The final summary message when a "perl -c" succeeds.

   sysread() on closed filehandle %s
       (W closed) You tried to read from a closed filehandle.

   sysread() on unopened filehandle %s
       (W unopened) You tried to read from a filehandle that was never
       opened.

   System V %s is not implemented on this machine
       (F) You tried to do something with a function beginning with "sem",
       "shm", or "msg" but that System V IPC is not implemented in your
       machine.  In some machines the functionality can exist but be
       unconfigured.  Consult your system support.

   syswrite() on closed filehandle %s
       (W closed) The filehandle you're writing to got itself closed
       sometime before now.  Check your control flow.

   "-T" and "-B" not implemented on filehandles
       (F) Perl can't peek at the stdio buffer of filehandles when it
       doesn't know about your kind of stdio.  You'll have to use a
       filename instead.

   Target of goto is too deeply nested
       (F) You tried to use "goto" to reach a label that was too deeply
       nested for Perl to reach.  Perl is doing you a favor by refusing.

   telldir() attempted on invalid dirhandle %s
       (W io) The dirhandle you tried to telldir() is either closed or not
       really a dirhandle.  Check your control flow.

   tell() on unopened filehandle
       (W unopened) You tried to use the tell() function on a filehandle
       that was either never opened or has since been closed.

   That use of $[ is unsupported
       (F) Assignment to $[ is now strictly circumscribed, and interpreted
       as a compiler directive.  You may say only one of

           $[ = 0;
           $[ = 1;
           ...
           local $[ = 0;
           local $[ = 1;
           ...

       This is to prevent the problem of one module changing the array
       base out from under another module inadvertently.  See "$[" in
       perlvar and arybase.

   The bitwise feature is experimental
       (S experimental::bitwise) This warning is emitted if you use
       bitwise operators ("& | ^ ~ &. |. ^. ~.") with the "bitwise"
       feature enabled.  Simply suppress the warning if you want to use
       the feature, but know that in doing so you are taking the risk of
       using an experimental feature which may change or be removed in a
       future Perl version:

           no warnings "experimental::bitwise";
           use feature "bitwise";
           $x |.= $y;

   The crypt() function is unimplemented due to excessive paranoia.
       (F) Configure couldn't find the crypt() function on your machine,
       probably because your vendor didn't supply it, probably because
       they think the U.S. Government thinks it's a secret, or at least
       that they will continue to pretend that it is.  And if you quote me
       on that, I will deny it.

   The %s function is unimplemented
       (F) The function indicated isn't implemented on this architecture,
       according to the probings of Configure.

   The lexical_subs feature is experimental
       (S experimental::lexical_subs) This warning is emitted if you
       declare a sub with "my" or "state".  Simply suppress the warning if
       you want to use the feature, but know that in doing so you are
       taking the risk of using an experimental feature which may change
       or be removed in a future Perl version:

           no warnings "experimental::lexical_subs";
           use feature "lexical_subs";
           my sub foo { ... }

   The regex_sets feature is experimental
       (S experimental::regex_sets) This warning is emitted if you use the
       syntax "(?[])" in a regular expression.  The details of this
       feature are subject to change.  if you want to use it, but know
       that in doing so you are taking the risk of using an experimental
       feature which may change in a future Perl version, you can do this
       to silence the warning:

           no warnings "experimental::regex_sets";

   The signatures feature is experimental
       (S experimental::signatures) This warning is emitted if you unwrap
       a subroutine's arguments using a signature.  Simply suppress the
       warning if you want to use the feature, but know that in doing so
       you are taking the risk of using an experimental feature which may
       change or be removed in a future Perl version:

           no warnings "experimental::signatures";
           use feature "signatures";
           sub foo ($left, $right) { ... }

   The stat preceding %s wasn't an lstat
       (F) It makes no sense to test the current stat buffer for symbolic
       linkhood if the last stat that wrote to the stat buffer already
       went past the symlink to get to the real file.  Use an actual
       filename instead.

   The 'unique' attribute may only be applied to 'our' variables
       (F) This attribute was never supported on "my" or "sub"
       declarations.

   This Perl can't reset CRTL environ elements (%s)
   This Perl can't set CRTL environ elements (%s=%s)
       (W internal) Warnings peculiar to VMS.  You tried to change or
       delete an element of the CRTL's internal environ array, but your
       copy of Perl wasn't built with a CRTL that contained the setenv()
       function.  You'll need to rebuild Perl with a CRTL that does, or
       redefine PERL_ENV_TABLES (see perlvms) so that the environ array
       isn't the target of the change to %ENV which produced the warning.

   This Perl has not been built with support for randomized hash key
   traversal but something called Perl_hv_rand_set().
       (F) Something has attempted to use an internal API call which
       depends on Perl being compiled with the default support for
       randomized hash key traversal, but this Perl has been compiled
       without it.  You should report this warning to the relevant
       upstream party, or recompile perl with default options.

   times not implemented
       (F) Your version of the C library apparently doesn't do times().  I
       suspect you're not running on Unix.

   "-T" is on the #! line, it must also be used on the command line
       (X) The #! line (or local equivalent) in a Perl script contains the
       -T option (or the -t option), but Perl was not invoked with -T in
       its command line.  This is an error because, by the time Perl
       discovers a -T in a script, it's too late to properly taint
       everything from the environment.  So Perl gives up.

       If the Perl script is being executed as a command using the #!
       mechanism (or its local equivalent), this error can usually be
       fixed by editing the #! line so that the -%c option is a part of
       Perl's first argument: e.g. change "perl -n -%c" to "perl -%c -n".

       If the Perl script is being executed as "perl scriptname", then the
       -%c option must appear on the command line: "perl -%c scriptname".

   To%s: illegal mapping '%s'
       (F) You tried to define a customized To-mapping for lc(), lcfirst,
       uc(), or ucfirst() (or their string-inlined versions), but you
       specified an illegal mapping.  See "User-Defined Character
       Properties" in perlunicode.

   Too deeply nested ()-groups
       (F) Your template contains ()-groups with a ridiculously deep
       nesting level.

   Too few args to syscall
       (F) There has to be at least one argument to syscall() to specify
       the system call to call, silly dilly.

   Too few arguments for subroutine
       (F) A subroutine using a signature received fewer arguments than
       required by the signature.  The caller of the subroutine is
       presumably at fault.  Inconveniently, this error will be reported
       at the location of the subroutine, not that of the caller.

   Too late for "-%s" option
       (X) The #! line (or local equivalent) in a Perl script contains the
       -M, -m or -C option.

       In the case of -M and -m, this is an error because those options
       are not intended for use inside scripts.  Use the "use" pragma
       instead.

       The -C option only works if it is specified on the command line as
       well (with the same sequence of letters or numbers following).
       Either specify this option on the command line, or, if your system
       supports it, make your script executable and run it directly
       instead of passing it to perl.

   Too late to run %s block
       (W void) A CHECK or INIT block is being defined during run time
       proper, when the opportunity to run them has already passed.
       Perhaps you are loading a file with "require" or "do" when you
       should be using "use" instead.  Or perhaps you should put the
       "require" or "do" inside a BEGIN block.

   Too many args to syscall
       (F) Perl supports a maximum of only 14 args to syscall().

   Too many arguments for %s
       (F) The function requires fewer arguments than you specified.

   Too many arguments for subroutine
       (F) A subroutine using a signature received more arguments than
       required by the signature.  The caller of the subroutine is
       presumably at fault.  Inconveniently, this error will be reported
       at the location of the subroutine, not that of the caller.

   Too many )'s
       (A) You've accidentally run your script through csh instead of
       Perl.  Check the #! line, or manually feed your script into Perl
       yourself.

   Too many ('s
       (A) You've accidentally run your script through csh instead of
       Perl.  Check the #! line, or manually feed your script into Perl
       yourself.

   Trailing \ in regex m/%s/
       (F) The regular expression ends with an unbackslashed backslash.
       Backslash it.   See perlre.

   Transliteration pattern not terminated
       (F) The lexer couldn't find the interior delimiter of a tr/// or
       tr[][] or y/// or y[][] construct.  Missing the leading "$" from
       variables $tr or $y may cause this error.

   Transliteration replacement not terminated
       (F) The lexer couldn't find the final delimiter of a tr///, tr[][],
       y/// or y[][] construct.

   '%s' trapped by operation mask
       (F) You tried to use an operator from a Safe compartment in which
       it's disallowed.  See Safe.

   truncate not implemented
       (F) Your machine doesn't implement a file truncation mechanism that
       Configure knows about.

   Type of arg %d to &CORE::%s must be %s
       (F) The subroutine in question in the CORE package requires its
       argument to be a hard reference to data of the specified type.
       Overloading is ignored, so a reference to an object that is not the
       specified type, but nonetheless has overloading to handle it, will
       still not be accepted.

   Type of arg %d to %s must be %s (not %s)
       (F) This function requires the argument in that position to be of a
       certain type.  Arrays must be @NAME or "@{EXPR}".  Hashes must be
       %NAME or "%{EXPR}".  No implicit dereferencing is allowed--use the
       {EXPR} forms as an explicit dereference.  See perlref.

   umask not implemented
       (F) Your machine doesn't implement the umask function and you tried
       to use it to restrict permissions for yourself (EXPR & 0700).

   Unbalanced context: %d more PUSHes than POPs
       (S internal) The exit code detected an internal inconsistency in
       how many execution contexts were entered and left.

   Unbalanced saves: %d more saves than restores
       (S internal) The exit code detected an internal inconsistency in
       how many values were temporarily localized.

   Unbalanced scopes: %d more ENTERs than LEAVEs
       (S internal) The exit code detected an internal inconsistency in
       how many blocks were entered and left.

   Unbalanced string table refcount: (%d) for "%s"
       (S internal) On exit, Perl found some strings remaining in the
       shared string table used for copy on write and for hash keys.  The
       entries should have been freed, so this indicates a bug somewhere.

   Unbalanced tmps: %d more allocs than frees
       (S internal) The exit code detected an internal inconsistency in
       how many mortal scalars were allocated and freed.

   Undefined format "%s" called
       (F) The format indicated doesn't seem to exist.  Perhaps it's
       really in another package?  See perlform.

   Undefined sort subroutine "%s" called
       (F) The sort comparison routine specified doesn't seem to exist.
       Perhaps it's in a different package?  See "sort" in perlfunc.

   Undefined subroutine &%s called
       (F) The subroutine indicated hasn't been defined, or if it was, it
       has since been undefined.

   Undefined subroutine called
       (F) The anonymous subroutine you're trying to call hasn't been
       defined, or if it was, it has since been undefined.

   Undefined subroutine in sort
       (F) The sort comparison routine specified is declared but doesn't
       seem to have been defined yet.  See "sort" in perlfunc.

   Undefined top format "%s" called
       (F) The format indicated doesn't seem to exist.  Perhaps it's
       really in another package?  See perlform.

   Undefined value assigned to typeglob
       (W misc) An undefined value was assigned to a typeglob, a la "*foo
       = undef".  This does nothing.  It's possible that you really mean
       "undef *foo".

   %s: Undefined variable
       (A) You've accidentally run your script through csh instead of
       Perl.  Check the #! line, or manually feed your script into Perl
       yourself.

   Unescaped left brace in regex is deprecated, passed through in regex;
   marked by <--HERE in m/%s/
       (D deprecated, regexp) You used a literal "{" character in a
       regular expression pattern.  You should change to use "\{" instead,
       because a future version of Perl (tentatively v5.26) will consider
       this to be a syntax error.  If the pattern delimiters are also
       braces, any matching right brace ("}") should also be escaped to
       avoid confusing the parser, for example,

           qr{abc\{def\}ghi}

   unexec of %s into %s failed!
       (F) The unexec() routine failed for some reason.  See your local
       FSF representative, who probably put it there in the first place.

   Unexpected binary operator '%c' with no preceding operand in regex;
   marked by <--HERE in m/%s/
       (F) You had something like this:

        (?[ | \p{Digit} ])

       where the "|" is a binary operator with an operand on the right,
       but no operand on the left.

   Unexpected character in regex; marked by <--HERE in m/%s/
       (F) You had something like this:

        (?[ z ])

       Within "(?[ ])", no literal characters are allowed unless they are
       within an inner pair of square brackets, like

        (?[ [ z ] ])

       Another possibility is that you forgot a backslash.  Perl isn't
       smart enough to figure out what you really meant.

   Unexpected constant lvalue entersub entry via type/targ %d:%d
       (P) When compiling a subroutine call in lvalue context, Perl failed
       an internal consistency check.  It encountered a malformed op tree.

   Unexpected exit %u
       (S) exit() was called or the script otherwise finished gracefully
       when "PERL_EXIT_WARN" was set in "PL_exit_flags".

   Unexpected exit failure %d
       (S) An uncaught die() was called when "PERL_EXIT_WARN" was set in
       "PL_exit_flags".

   Unexpected ')' in regex; marked by <--HERE in m/%s/
       (F) You had something like this:

        (?[ ( \p{Digit} + ) ])

       The ")" is out-of-place.  Something apparently was supposed to be
       combined with the digits, or the "+" shouldn't be there, or
       something like that.  Perl can't figure out what was intended.

   Unexpected '(' with no preceding operator in regex; marked by <--HERE
   in m/%s/
       (F) You had something like this:

        (?[ \p{Digit} ( \p{Lao} + \p{Thai} ) ])

       There should be an operator before the "(", as there's no
       indication as to how the digits are to be combined with the
       characters in the Lao and Thai scripts.

   Unicode non-character U+%X is not recommended for open interchange
       (S nonchar) Certain codepoints, such as U+FFFE and U+FFFF, are
       defined by the Unicode standard to be non-characters.  Those are
       legal codepoints, but are reserved for internal use; so,
       applications shouldn't attempt to exchange them.  An application
       may not be expecting any of these characters at all, and receiving
       them may lead to bugs.  If you know what you are doing you can turn
       off this warning by "no warnings 'nonchar';".

       This is not really a "severe" error, but it is supposed to be
       raised by default even if warnings are not enabled, and currently
       the only way to do that in Perl is to mark it as serious.

   Unicode surrogate U+%X is illegal in UTF-8
       (S surrogate) You had a UTF-16 surrogate in a context where they
       are not considered acceptable.  These code points, between U+D800
       and U+DFFF (inclusive), are used by Unicode only for UTF-16.
       However, Perl internally allows all unsigned integer code points
       (up to the size limit available on your platform), including
       surrogates.  But these can cause problems when being input or
       output, which is likely where this message came from.  If you
       really really know what you are doing you can turn off this warning
       by "no warnings 'surrogate';".

   Unknown charname '' is deprecated
       (D deprecated) You had a "\N{}" with nothing between the braces.
       This usage is deprecated, and will be made a syntax error in a
       future Perl version.

   Unknown charname '%s'
       (F) The name you used inside "\N{}" is unknown to Perl.  Check the
       spelling.  You can say "use charnames ":loose"" to not have to be
       so precise about spaces, hyphens, and capitalization on standard
       Unicode names.  (Any custom aliases that have been created must be
       specified exactly, regardless of whether ":loose" is used or not.)
       This error may also happen if the "\N{}" is not in the scope of the
       corresponding "usecharnames".

   Unknown error
       (P) Perl was about to print an error message in $@, but the $@
       variable did not exist, even after an attempt to create it.

   Unknown open() mode '%s'
       (F) The second argument of 3-argument open() is not among the list
       of valid modes: "<", ">", ">>", "+<", "+>", "+>>", "-|", "|-",
       "<&", ">&".

   Unknown PerlIO layer "%s"
       (W layer) An attempt was made to push an unknown layer onto the
       Perl I/O system.  (Layers take care of transforming data between
       external and internal representations.)  Note that some layers,
       such as "mmap", are not supported in all environments.  If your
       program didn't explicitly request the failing operation, it may be
       the result of the value of the environment variable PERLIO.

   Unknown process %x sent message to prime_env_iter: %s
       (P) An error peculiar to VMS.  Perl was reading values for %ENV
       before iterating over it, and someone else stuck a message in the
       stream of data Perl expected.  Someone's very confused, or perhaps
       trying to subvert Perl's population of %ENV for nefarious purposes.

   Unknown regex modifier "%s"
       (F) Alphanumerics immediately following the closing delimiter of a
       regular expression pattern are interpreted by Perl as modifier
       flags for the regex.  One of the ones you specified is invalid.
       One way this can happen is if you didn't put in white space between
       the end of the regex and a following alphanumeric operator:

        if ($a =~ /foo/and $bar == 3) { ... }

       The "a" is a valid modifier flag, but the "n" is not, and raises
       this error.  Likely what was meant instead was:

        if ($a =~ /foo/ and $bar == 3) { ... }

   Unknown "re" subpragma '%s' (known ones are: %s)
       (W) You tried to use an unknown subpragma of the "re" pragma.

   Unknown switch condition (?(...)) in regex; marked by <--HERE in m/%s/
       (F) The condition part of a (?(condition)if-clause|else-clause)
       construct is not known.  The condition must be one of the
       following:

        (1) (2) ...        true if 1st, 2nd, etc., capture matched
        (<NAME>) ('NAME')  true if named capture matched
        (?=...) (?<=...)   true if subpattern matches
        (?!...) (?<!...)   true if subpattern fails to match
        (?{ CODE })        true if code returns a true value
        (R)                true if evaluating inside recursion
        (R1) (R2) ...      true if directly inside capture group 1, 2, etc.
        (R&NAME)           true if directly inside named capture
        (DEFINE)           always false; for defining named subpatterns

       The <--HERE shows whereabouts in the regular expression the
       problem was discovered.  See perlre.

   Unknown Unicode option letter '%c'
       (F) You specified an unknown Unicode option.  See perlrun
       documentation of the "-C" switch for the list of known options.

   Unknown Unicode option value %d
       (F) You specified an unknown Unicode option.  See perlrun
       documentation of the "-C" switch for the list of known options.

   Unknown verb pattern '%s' in regex; marked by <--HERE in m/%s/
       (F) You either made a typo or have incorrectly put a "*" quantifier
       after an open brace in your pattern.  Check the pattern and review
       perlre for details on legal verb patterns.

   Unknown warnings category '%s'
       (F) An error issued by the "warnings" pragma.  You specified a
       warnings category that is unknown to perl at this point.

       Note that if you want to enable a warnings category registered by a
       module (e.g. "use warnings 'File::Find'"), you must have loaded
       this module first.

   Unmatched [ in regex; marked by <--HERE in m/%s/
       (F) The brackets around a character class must match.  If you wish
       to include a closing bracket in a character class, backslash it or
       put it first.  The <--HERE shows whereabouts in the regular
       expression the problem was discovered.  See perlre.

   Unmatched ( in regex; marked by <--HERE in m/%s/
   Unmatched ) in regex; marked by <--HERE in m/%s/
       (F) Unbackslashed parentheses must always be balanced in regular
       expressions.  If you're a vi user, the % key is valuable for
       finding the matching parenthesis.  The <--HERE shows whereabouts
       in the regular expression the problem was discovered.  See perlre.

   Unmatched right %s bracket
       (F) The lexer counted more closing curly or square brackets than
       opening ones, so you're probably missing a matching opening
       bracket.  As a general rule, you'll find the missing one (so to
       speak) near the place you were last editing.

   Unquoted string "%s" may clash with future reserved word
       (W reserved) You used a bareword that might someday be claimed as a
       reserved word.  It's best to put such a word in quotes, or
       capitalize it somehow, or insert an underbar into it.  You might
       also declare it as a subroutine.

   Unrecognized character %s; marked by <--HERE after %s near column %d
       (F) The Perl parser has no idea what to do with the specified
       character in your Perl script (or eval) near the specified column.
       Perhaps you tried  to run a compressed script, a binary program, or
       a directory as a Perl program.

   Unrecognized escape \%c in character class in regex; marked by <--HERE
   in m/%s/
       (F) You used a backslash-character combination which is not
       recognized by Perl inside character classes.  This is a fatal error
       when the character class is used within "(?[ ])".

   Unrecognized escape \%c in character class passed through in regex;
   marked by <--HERE in m/%s/
       (W regexp) You used a backslash-character combination which is not
       recognized by Perl inside character classes.  The character was
       understood literally, but this may change in a future version of
       Perl.  The <--HERE shows whereabouts in the regular expression the
       escape was discovered.

   Unrecognized escape \%c passed through
       (W misc) You used a backslash-character combination which is not
       recognized by Perl.  The character was understood literally, but
       this may change in a future version of Perl.

   Unrecognized escape \%s passed through in regex; marked by <--HERE in
   m/%s/
       (W regexp) You used a backslash-character combination which is not
       recognized by Perl.  The character(s) were understood literally,
       but this may change in a future version of Perl.  The <--HERE
       shows whereabouts in the regular expression the escape was
       discovered.

   Unrecognized signal name "%s"
       (F) You specified a signal name to the kill() function that was not
       recognized.  Say "kill -l" in your shell to see the valid signal
       names on your system.

   Unrecognized switch: -%s  (-h will show valid options)
       (F) You specified an illegal option to Perl.  Don't do that.  (If
       you think you didn't do that, check the #! line to see if it's
       supplying the bad switch on your behalf.)

   Unsuccessful %s on filename containing newline
       (W newline) A file operation was attempted on a filename, and that
       operation failed, PROBABLY because the filename contained a
       newline, PROBABLY because you forgot to chomp() it off.  See
       "chomp" in perlfunc.

   Unsupported directory function "%s" called
       (F) Your machine doesn't support opendir() and readdir().

   Unsupported function %s
       (F) This machine doesn't implement the indicated function,
       apparently.  At least, Configure doesn't think so.

   Unsupported function fork
       (F) Your version of executable does not support forking.

       Note that under some systems, like OS/2, there may be different
       flavors of Perl executables, some of which may support fork, some
       not.  Try changing the name you call Perl by to "perl_", "perl__",
       and so on.

   Unsupported script encoding %s
       (F) Your program file begins with a Unicode Byte Order Mark (BOM)
       which declares it to be in a Unicode encoding that Perl cannot
       read.

   Unsupported socket function "%s" called
       (F) Your machine doesn't support the Berkeley socket mechanism, or
       at least that's what Configure thought.

   Unterminated attribute list
       (F) The lexer found something other than a simple identifier at the
       start of an attribute, and it wasn't a semicolon or the start of a
       block.  Perhaps you terminated the parameter list of the previous
       attribute too soon.  See attributes.

   Unterminated attribute parameter in attribute list
       (F) The lexer saw an opening (left) parenthesis character while
       parsing an attribute list, but the matching closing (right)
       parenthesis character was not found.  You may need to add (or
       remove) a backslash character to get your parentheses to balance.
       See attributes.

   Unterminated compressed integer
       (F) An argument to unpack("w",...) was incompatible with the BER
       compressed integer format and could not be converted to an integer.
       See "pack" in perlfunc.

   Unterminated delimiter for here document
       (F) This message occurs when a here document label has an initial
       quotation mark but the final quotation mark is missing.  Perhaps
       you wrote:

           <<"foo

       instead of:

           <<"foo"

   Unterminated \g... pattern in regex; marked by <--HERE in m/%s/
   Unterminated \g{...} pattern in regex; marked by <--HERE in m/%s/
       (F) In a regular expression, you had a "\g" that wasn't followed by
       a proper group reference.  In the case of "\g{", the closing brace
       is missing; otherwise the "\g" must be followed by an integer.  Fix
       the pattern and retry.

   Unterminated <> operator
       (F) The lexer saw a left angle bracket in a place where it was
       expecting a term, so it's looking for the corresponding right angle
       bracket, and not finding it.  Chances are you left some needed
       parentheses out earlier in the line, and you really meant a "less
       than".

   Unterminated verb pattern argument in regex; marked by <--HERE in
   m/%s/
       (F) You used a pattern of the form "(*VERB:ARG)" but did not
       terminate the pattern with a ")".  Fix the pattern and retry.

   Unterminated verb pattern in regex; marked by <--HERE in m/%s/
       (F) You used a pattern of the form "(*VERB)" but did not terminate
       the pattern with a ")".  Fix the pattern and retry.

   untie attempted while %d inner references still exist
       (W untie) A copy of the object returned from "tie" (or "tied") was
       still valid when "untie" was called.

   Usage: POSIX::%s(%s)
       (F) You called a POSIX function with incorrect arguments.  See
       "FUNCTIONS" in POSIX for more information.

   Usage: Win32::%s(%s)
       (F) You called a Win32 function with incorrect arguments.  See
       Win32 for more information.

   $[ used in %s (did you mean $] ?)
       (W syntax) You used $[ in a comparison, such as:

           if ($[ > 5.006) {
               ...
           }

       You probably meant to use $] instead.  $[ is the base for indexing
       arrays.  $] is the Perl version number in decimal.

   Use "%s" instead of "%s"
       (F) The second listed construct is no longer legal.  Use the first
       one instead.

   Useless assignment to a temporary
       (W misc) You assigned to an lvalue subroutine, but what the
       subroutine returned was a temporary scalar about to be discarded,
       so the assignment had no effect.

   Useless (?-%s) - don't use /%s modifier in regex; marked by <--HERE in
   m/%s/
       (W regexp) You have used an internal modifier such as (?-o) that
       has no meaning unless removed from the entire regexp:

           if ($string =~ /(?-o)$pattern/o) { ... }

       must be written as

           if ($string =~ /$pattern/) { ... }

       The <--HERE shows whereabouts in the regular expression the
       problem was discovered.  See perlre.

   Useless localization of %s
       (W syntax) The localization of lvalues such as "local($x=10)" is
       legal, but in fact the local() currently has no effect.  This may
       change at some point in the future, but in the meantime such code
       is discouraged.

   Useless (?%s) - use /%s modifier in regex; marked by <--HERE in m/%s/
       (W regexp) You have used an internal modifier such as (?o) that has
       no meaning unless applied to the entire regexp:

           if ($string =~ /(?o)$pattern/) { ... }

       must be written as

           if ($string =~ /$pattern/o) { ... }

       The <--HERE shows whereabouts in the regular expression the
       problem was discovered.  See perlre.

   Useless use of attribute "const"
       (W misc) The "const" attribute has no effect except on anonymous
       closure prototypes.  You applied it to a subroutine via
       attributes.pm.  This is only useful inside an attribute handler for
       an anonymous subroutine.

   Useless use of /d modifier in transliteration operator
       (W misc) You have used the /d modifier where the searchlist has the
       same length as the replacelist.  See perlop for more information
       about the /d modifier.

   Useless use of \E
       (W misc) You have a \E in a double-quotish string without a "\U",
       "\L" or "\Q" preceding it.

   Useless use of greediness modifier '%c' in regex; marked by <--HERE in
   m/%s/
       (W regexp) You specified something like these:

        qr/a{3}?/
        qr/b{1,1}+/

       The "?" and "+" don't have any effect, as they modify whether to
       match more or fewer when there is a choice, and by specifying to
       match exactly a given numer, there is no room left for a choice.

   Useless use of %s in void context
       (W void) You did something without a side effect in a context that
       does nothing with the return value, such as a statement that
       doesn't return a value from a block, or the left side of a scalar
       comma operator.  Very often this points not to stupidity on your
       part, but a failure of Perl to parse your program the way you
       thought it would.  For example, you'd get this if you mixed up your
       C precedence with Python precedence and said

           $one, $two = 1, 2;

       when you meant to say

           ($one, $two) = (1, 2);

       Another common error is to use ordinary parentheses to construct a
       list reference when you should be using square or curly brackets,
       for example, if you say

           $array = (1,2);

       when you should have said

           $array = [1,2];

       The square brackets explicitly turn a list value into a scalar
       value, while parentheses do not.  So when a parenthesized list is
       evaluated in a scalar context, the comma is treated like C's comma
       operator, which throws away the left argument, which is not what
       you want.  See perlref for more on this.

       This warning will not be issued for numerical constants equal to 0
       or 1 since they are often used in statements like

           1 while sub_with_side_effects();

       String constants that would normally evaluate to 0 or 1 are warned
       about.

   Useless use of (?-p) in regex; marked by <--HERE in m/%s/
       (W regexp) The "p" modifier cannot be turned off once set.  Trying
       to do so is futile.

   Useless use of "re" pragma
       (W) You did "use re;" without any arguments.  That isn't very
       useful.

   Useless use of sort in scalar context
       (W void) You used sort in scalar context, as in :

           my $x = sort @y;

       This is not very useful, and perl currently optimizes this away.

   Useless use of %s with no values
       (W syntax) You used the push() or unshift() function with no
       arguments apart from the array, like "push(@x)" or "unshift(@foo)".
       That won't usually have any effect on the array, so is completely
       useless.  It's possible in principle that push(@tied_array) could
       have some effect if the array is tied to a class which implements a
       PUSH method.  If so, you can write it as "push(@tied_array,())" to
       avoid this warning.

   "use" not allowed in expression
       (F) The "use" keyword is recognized and executed at compile time,
       and returns no useful value.  See perlmod.

   Use of assignment to $[ is deprecated
       (D deprecated) The $[ variable (index of the first element in an
       array) is deprecated.  See "$[" in perlvar.

   Use of bare << to mean <<"" is deprecated
       (D deprecated) You are now encouraged to use the explicitly quoted
       form if you wish to use an empty line as the terminator of the
       here-document.

   Use of /c modifier is meaningless in s///
       (W regexp) You used the /c modifier in a substitution.  The /c
       modifier is not presently meaningful in substitutions.

   Use of /c modifier is meaningless without /g
       (W regexp) You used the /c modifier with a regex operand, but
       didn't use the /g modifier.  Currently, /c is meaningful only when
       /g is used.  (This may change in the future.)

   Use of code point 0x%s is deprecated; the permissible max is 0x%s
       (D deprecated) You used a code point that will not be allowed in a
       future perl version, because it is too large.  Unicode only allows
       code points up to 0x10FFFF, but Perl allows much larger ones.
       However, the largest possible ones break the perl interpreter in
       some constructs, including causing it to hang in a few cases.  The
       known problem areas are in "tr///", regular expression pattern
       matching using quantifiers, and as the upper limits in loops.

       If your code is to run on various platforms, keep in mind that the
       upper limit depends on the platform.  It is much larger on 64-bit
       word sizes than 32-bit ones.

   Use of comma-less variable list is deprecated
       (D deprecated) The values you give to a format should be separated
       by commas, not just aligned on a line.

   Use of each() on hash after insertion without resetting hash iterator
   results in undefined behavior
       (S internal) The behavior of "each()" after insertion is undefined;
       it may skip items, or visit items more than once.  Consider using
       "keys()" instead of "each()".

   Use of := for an empty attribute list is not allowed
       (F) The construction "my $x := 42" used to parse as equivalent to
       "my $x : = 42" (applying an empty attribute list to $x).  This
       construct was deprecated in 5.12.0, and has now been made a syntax
       error, so ":=" can be reclaimed as a new operator in the future.

       If you need an empty attribute list, for example in a code
       generator, add a space before the "=".

   Use of %s for non-UTF-8 locale is wrong.  Assuming a UTF-8 locale
       (W locale)  You are matching a regular expression using locale
       rules, and the specified construct was encountered.  This construct
       is only valid for UTF-8 locales, which the current locale isn't.
       This doesn't make sense.  Perl will continue, assuming a Unicode
       (UTF-8) locale, but the results are likely to be wrong.

   Use of freed value in iteration
       (F) Perhaps you modified the iterated array within the loop?  This
       error is typically caused by code like the following:

           @a = (3,4);
           @a = () for (1,2,@a);

       You are not supposed to modify arrays while they are being iterated
       over.  For speed and efficiency reasons, Perl internally does not
       do full reference-counting of iterated items, hence deleting such
       an item in the middle of an iteration causes Perl to see a freed
       value.

   Use of *glob{FILEHANDLE} is deprecated
       (D deprecated) You are now encouraged to use the shorter *glob{IO}
       form to access the filehandle slot within a typeglob.

   Use of /g modifier is meaningless in split
       (W regexp) You used the /g modifier on the pattern for a "split"
       operator.  Since "split" always tries to match the pattern
       repeatedly, the "/g" has no effect.

   Use of "goto" to jump into a construct is deprecated
       (D deprecated) Using "goto" to jump from an outer scope into an
       inner scope is deprecated and should be avoided.

   Use of inherited AUTOLOAD for non-method %s() is deprecated
       (D deprecated) As an (ahem) accidental feature, "AUTOLOAD"
       subroutines are looked up as methods (using the @ISA hierarchy)
       even when the subroutines to be autoloaded were called as plain
       functions (e.g. "Foo::bar()"), not as methods (e.g. "Foo->bar()" or
       "$obj->bar()").

       This bug will be rectified in future by using method lookup only
       for methods' "AUTOLOAD"s.  However, there is a significant base of
       existing code that may be using the old behavior.  So, as an
       interim step, Perl currently issues an optional warning when non-
       methods use inherited "AUTOLOAD"s.

       The simple rule is:  Inheritance will not work when autoloading
       non-methods.  The simple fix for old code is:  In any module that
       used to depend on inheriting "AUTOLOAD" for non-methods from a base
       class named "BaseClass", execute "*AUTOLOAD =
       \&BaseClass::AUTOLOAD" during startup.

       In code that currently says "use AutoLoader; @ISA =
       qw(AutoLoader);" you should remove AutoLoader from @ISA and change
       "use AutoLoader;" to "use AutoLoader 'AUTOLOAD';".

   Use of %s in printf format not supported
       (F) You attempted to use a feature of printf that is accessible
       from only C.  This usually means there's a better way to do it in
       Perl.

   Use of %s is deprecated
       (D deprecated) The construct indicated is no longer recommended for
       use, generally because there's a better way to do it, and also
       because the old way has bad side effects.

   Use of literal control characters in variable names is deprecated
   Use of literal non-graphic characters in variable names is deprecated
       (D deprecated) Using literal non-graphic (including control)
       characters in the source to refer to the ^FOO variables, like $^X
       and "${^GLOBAL_PHASE}" is now deprecated.  (We use "^X" and "^G"
       here for legibility.  They actually represent the non-printable
       control characters, code points 0x18 and 0x07, respectively; "^A"
       would mean the control character whose code point is 0x01.) This
       only affects code like "$\cT", where "\cT" is a control in the
       source code; "${"\cT"}" and $^T remain valid.  Things that are non-
       controls and also not graphic are NO-BREAK SPACE and SOFT HYPHEN,
       which were previously only allowed for historical reasons.

   Use of -l on filehandle%s
       (W io) A filehandle represents an opened file, and when you opened
       the file it already went past any symlink you are presumably trying
       to look for.  The operation returned "undef".  Use a filename
       instead.

   Use of %s on a handle without * is deprecated
       (D deprecated) You used "tie", "tied" or "untie" on a scalar but
       that scalar happens to hold a typeglob, which means its filehandle
       will be tied.  If you mean to tie a handle, use an explicit * as in
       "tie *$handle".

       This was a long-standing bug that was removed in Perl 5.16, as
       there was no way to tie the scalar itself when it held a typeglob,
       and no way to untie a scalar that had had a typeglob assigned to
       it.  If you see this message, you must be using an older version.

   Use of reference "%s" as array index
       (W misc) You tried to use a reference as an array index; this
       probably isn't what you mean, because references in numerical
       context tend to be huge numbers, and so usually indicates
       programmer error.

       If you really do mean it, explicitly numify your reference, like
       so: $array[0+$ref].  This warning is not given for overloaded
       objects, however, because you can overload the numification and
       stringification operators and then you presumably know what you are
       doing.

   Use of state $_ is experimental
       (S experimental::lexical_topic) Lexical $_ is an experimental
       feature and its behavior may change or even be removed in any
       future release of perl.  See the explanation under "$_" in perlvar.

   Use of strings with code points over 0xFF as arguments to %s operator
   is deprecated
       (D deprecated) You tried to use one of the string bitwise operators
       ("&" or "|" or "^" or "~") on a string containing a code point over
       0xFF.  The string bitwise operators treat their operands as strings
       of bytes, and values beyond 0xFF are nonsensical in this context.

   Use of tainted arguments in %s is deprecated
       (W taint, deprecated) You have supplied "system()" or "exec()" with
       multiple arguments and at least one of them is tainted.  This used
       to be allowed but will become a fatal error in a future version of
       perl.  Untaint your arguments.  See perlsec.

   Use of uninitialized value%s
       (W uninitialized) An undefined value was used as if it were already
       defined.  It was interpreted as a "" or a 0, but maybe it was a
       mistake.  To suppress this warning assign a defined value to your
       variables.

       To help you figure out what was undefined, perl will try to tell
       you the name of the variable (if any) that was undefined.  In some
       cases it cannot do this, so it also tells you what operation you
       used the undefined value in.  Note, however, that perl optimizes
       your program and the operation displayed in the warning may not
       necessarily appear literally in your program.  For example, "that
       $foo" is usually optimized into ""that " . $foo", and the warning
       will refer to the "concatenation (.)" operator, even though there
       is no "." in your program.

   "use re 'strict'" is experimental
       (S experimental::re_strict) The things that are different when a
       regular expression pattern is compiled under 'strict' are subject
       to change in future Perl releases in incompatible ways.  This means
       that a pattern that compiles today may not in a future Perl
       release.  This warning is to alert you to that risk.

   Use \x{...} for more than two hex characters in regex; marked by
   <--HERE in m/%s/
       (F) In a regular expression, you said something like

        (?[ [ \xBEEF ] ])

       Perl isn't sure if you meant this

        (?[ [ \x{BEEF} ] ])

       or if you meant this

        (?[ [ \x{BE} E F ] ])

       You need to add either braces or blanks to disambiguate.

   Using just the first character returned by \N{} in character class in
   regex; marked by <--HERE in m/%s/
       (W regexp) Named Unicode character escapes "(\N{...})" may return a
       multi-character sequence.  Even though a character class is
       supposed to match just one character of input, perl will match the
       whole thing correctly, except when the class is inverted
       ("[^...]"), or the escape is the beginning or final end point of a
       range.  For these, what should happen isn't clear at all.  In these
       circumstances, Perl discards all but the first character of the
       returned sequence, which is not likely what you want.

   Using /u for '%s' instead of /%s in regex; marked by <--HERE in m/%s/
       (W regexp) You used a Unicode boundary ("	{...}" or "\B{...}") in
       a portion of a regular expression where the character set modifiers
       "/a" or "/aa" are in effect.  These two modifiers indicate an ASCII
       interpretation, and this doesn't make sense for a Unicode
       defintion.  The generated regular expression will compile so that
       the boundary uses all of Unicode.  No other portion of the regular
       expression is affected.

   Using !~ with %s doesn't make sense
       (F) Using the "!~" operator with "s///r", "tr///r" or "y///r" is
       currently reserved for future use, as the exact behavior has not
       been decided.  (Simply returning the boolean opposite of the
       modified string is usually not particularly useful.)

   UTF-16 surrogate U+%X
       (S surrogate) You had a UTF-16 surrogate in a context where they
       are not considered acceptable.  These code points, between U+D800
       and U+DFFF (inclusive), are used by Unicode only for UTF-16.
       However, Perl internally allows all unsigned integer code points
       (up to the size limit available on your platform), including
       surrogates.  But these can cause problems when being input or
       output, which is likely where this message came from.  If you
       really really know what you are doing you can turn off this warning
       by "no warnings 'surrogate';".

   Value of %s can be "0"; test with defined()
       (W misc) In a conditional expression, you used <HANDLE>, <*>
       (glob), "each()", or "readdir()" as a boolean value.  Each of these
       constructs can return a value of "0"; that would make the
       conditional expression false, which is probably not what you
       intended.  When using these constructs in conditional expressions,
       test their values with the "defined" operator.

   Value of CLI symbol "%s" too long
       (W misc) A warning peculiar to VMS.  Perl tried to read the value
       of an %ENV element from a CLI symbol table, and found a resultant
       string longer than 1024 characters.  The return value has been
       truncated to 1024 characters.

   Variable "%s" is not available
       (W closure) During compilation, an inner named subroutine or eval
       is attempting to capture an outer lexical that is not currently
       available.  This can happen for one of two reasons.  First, the
       outer lexical may be declared in an outer anonymous subroutine that
       has not yet been created.  (Remember that named subs are created at
       compile time, while anonymous subs are created at run-time.)  For
       example,

           sub { my $a; sub f { $a } }

       At the time that f is created, it can't capture the current value
       of $a, since the anonymous subroutine hasn't been created yet.
       Conversely, the following won't give a warning since the anonymous
       subroutine has by now been created and is live:

           sub { my $a; eval 'sub f { $a }' }->();

       The second situation is caused by an eval accessing a variable that
       has gone out of scope, for example,

           sub f {
               my $a;
               sub { eval '$a' }
           }
           f()->();

       Here, when the '$a' in the eval is being compiled, f() is not
       currently being executed, so its $a is not available for capture.

   Variable "%s" is not imported%s
       (S misc) With "use strict" in effect, you referred to a global
       variable that you apparently thought was imported from another
       module, because something else of the same name (usually a
       subroutine) is exported by that module.  It usually means you put
       the wrong funny character on the front of your variable.

   Variable length lookbehind not implemented in regex m/%s/
       (F) Lookbehind is allowed only for subexpressions whose length is
       fixed and known at compile time.  For positive lookbehind, you can
       use the "\K" regex construct as a way to get the equivalent
       functionality.  See "(?<=pattern) \K" in perlre.

       There are non-obvious Unicode rules under "/i" that can match
       variably, but which you might not think could.  For example, the
       substring "ss" can match the single character LATIN SMALL LETTER
       SHARP S.  There are other sequences of ASCII characters that can
       match single ligature characters, such as LATIN SMALL LIGATURE FFI
       matching "qr/ffi/i".  Starting in Perl v5.16, if you only care
       about ASCII matches, adding the "/aa" modifier to the regex will
       exclude all these non-obvious matches, thus getting rid of this
       message.  You can also say "usereqw(/aa)" to apply "/aa" to all
       regular expressions compiled within its scope.  See re.

   "%s" variable %s masks earlier declaration in same %s
       (W misc) A "my", "our" or "state" variable has been redeclared in
       the current scope or statement, effectively eliminating all access
       to the previous instance.  This is almost always a typographical
       error.  Note that the earlier variable will still exist until the
       end of the scope or until all closure references to it are
       destroyed.

   Variable syntax
       (A) You've accidentally run your script through csh instead of
       Perl.  Check the #! line, or manually feed your script into Perl
       yourself.

   Variable "%s" will not stay shared
       (W closure) An inner (nested) named subroutine is referencing a
       lexical variable defined in an outer named subroutine.

       When the inner subroutine is called, it will see the value of the
       outer subroutine's variable as it was before and during the *first*
       call to the outer subroutine; in this case, after the first call to
       the outer subroutine is complete, the inner and outer subroutines
       will no longer share a common value for the variable.  In other
       words, the variable will no longer be shared.

       This problem can usually be solved by making the inner subroutine
       anonymous, using the "sub {}" syntax.  When inner anonymous subs
       that reference variables in outer subroutines are created, they are
       automatically rebound to the current values of such variables.

   vector argument not supported with alpha versions
       (S printf) The %vd (s)printf format does not support version
       objects with alpha parts.

   Verb pattern '%s' has a mandatory argument in regex; marked by <--HERE
   in m/%s/
       (F) You used a verb pattern that requires an argument.  Supply an
       argument or check that you are using the right verb.

   Verb pattern '%s' may not have an argument in regex; marked by <--HERE
   in m/%s/
       (F) You used a verb pattern that is not allowed an argument.
       Remove the argument or check that you are using the right verb.

   Version number must be a constant number
       (P) The attempt to translate a "use Module n.n LIST" statement into
       its equivalent "BEGIN" block found an internal inconsistency with
       the version number.

   Version string '%s' contains invalid data; ignoring: '%s'
       (W misc) The version string contains invalid characters at the end,
       which are being ignored.

   Warning: something's wrong
       (W) You passed warn() an empty string (the equivalent of "warn """)
       or you called it with no args and $@ was empty.

   Warning: unable to close filehandle %s properly
       (S) The implicit close() done by an open() got an error indication
       on the close().  This usually indicates your file system ran out of
       disk space.

   Warning: unable to close filehandle properly: %s
   Warning: unable to close filehandle %s properly: %s
       (S io) There were errors during the implicit close() done on a
       filehandle when its reference count reached zero while it was still
       open, e.g.:

           {
               open my $fh, '>', $file  or die "open: '$file': $!\n";
               print $fh $data or die "print: $!";
           } # implicit close here

       Because various errors may only be detected by close() (e.g.
       buffering could allow the "print" in this example to return true
       even when the disk is full), it is dangerous to ignore its result.
       So when it happens implicitly, perl will signal errors by warning.

       Prior to version 5.22.0, perl ignored such errors, so the common
       idiom shown above was liable to cause silent data loss.

   Warning: Use of "%s" without parentheses is ambiguous
       (S ambiguous) You wrote a unary operator followed by something that
       looks like a binary operator that could also have been interpreted
       as a term or unary operator.  For instance, if you know that the
       rand function has a default argument of 1.0, and you write

           rand + 5;

       you may THINK you wrote the same thing as

           rand() + 5;

       but in actual fact, you got

           rand(+5);

       So put in parentheses to say what you really mean.

   when is experimental
       (S experimental::smartmatch) "when" depends on smartmatch, which is
       experimental.  Additionally, it has several special cases that may
       not be immediately obvious, and their behavior may change or even
       be removed in any future release of perl.  See the explanation
       under "Experimental Details on given and when" in perlsyn.

   Wide character in %s
       (S utf8) Perl met a wide character (>255) when it wasn't expecting
       one.  This warning is by default on for I/O (like print).  The
       easiest way to quiet this warning is simply to add the ":utf8"
       layer to the output, e.g. "binmode STDOUT, ':utf8'".  Another way
       to turn off the warning is to add "no warnings 'utf8';" but that is
       often closer to cheating.  In general, you are supposed to
       explicitly mark the filehandle with an encoding, see open and
       "binmode" in perlfunc.

   Wide character (U+%X) in %s
       (W locale) While in a single-byte locale (i.e., a non-UTF-8 one), a
       multi-byte character was encountered.   Perl considers this
       character to be the specified Unicode code point.  Combining
       non-UTF-8 locales and Unicode is dangerous.  Almost certainly some
       characters will have two different representations.  For example,
       in the ISO 8859-7 (Greek) locale, the code point 0xC3 represents a
       Capital Gamma.  But so also does 0x393.  This will make string
       comparisons unreliable.

       You likely need to figure out how this multi-byte character got
       mixed up with your single-byte locale (or perhaps you thought you
       had a UTF-8 locale, but Perl disagrees).

   Within []-length '%c' not allowed
       (F) The count in the (un)pack template may be replaced by
       "[TEMPLATE]" only if "TEMPLATE" always matches the same amount of
       packed bytes that can be determined from the template alone.  This
       is not possible if it contains any of the codes @, /, U, u, w or a
       *-length.  Redesign the template.

   %s() with negative argument
       (S misc) Certain operations make no sense with negative arguments.
       Warning is given and the operation is not done.

   write() on closed filehandle %s
       (W closed) The filehandle you're writing to got itself closed
       sometime before now.  Check your control flow.

   %s "\x%X" does not map to Unicode
       (S utf8) When reading in different encodings, Perl tries to map
       everything into Unicode characters.  The bytes you read in are not
       legal in this encoding.  For example

           utf8 "\xE4" does not map to Unicode

       if you try to read in the a-diaereses Latin-1 as UTF-8.

   'X' outside of string
       (F) You had a (un)pack template that specified a relative position
       before the beginning of the string being (un)packed.  See "pack" in
       perlfunc.

   'x' outside of string in unpack
       (F) You had a pack template that specified a relative position
       after the end of the string being unpacked.  See "pack" in
       perlfunc.

   YOU HAVEN'T DISABLED SET-ID SCRIPTS IN THE KERNEL YET!
       (F) And you probably never will, because you probably don't have
       the sources to your kernel, and your vendor probably doesn't give a
       rip about what you want.  Your best bet is to put a setuid C
       wrapper around your script.

   You need to quote "%s"
       (W syntax) You assigned a bareword as a signal handler name.
       Unfortunately, you already have a subroutine of that name declared,
       which means that Perl 5 will try to call the subroutine when the
       assignment is executed, which is probably not what you want.  (If
       it IS what you want, put an & in front.)

   Your random numbers are not that random
       (F) When trying to initialize the random seed for hashes, Perl
       could not get any randomness out of your system.  This usually
       indicates Something Very Wrong.

   Zero length \N{} in regex; marked by <--HERE in m/%s/
       (F) Named Unicode character escapes ("\N{...}") may return a zero-
       length sequence.  Such an escape was used in an extended character
       class, i.e.  "(?[...])", or under "use re 'strict'", which is not
       permitted.  Check that the correct escape has been used, and the
       correct charnames handler is in scope.  The <--HERE shows
       whereabouts in the regular expression the problem was discovered.

SEE ALSO

   warnings, diagnostics.





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