man > PERL5122DELTA(1)

PERL5122DELTA(1)                  Perl Programmers Reference Guide                  PERL5122DELTA(1)

NAME
       perl5122delta - what is new for perl v5.12.2

DESCRIPTION
       This document describes differences between the 5.12.1 release and the 5.12.2 release.

       If you are upgrading from an earlier major version, such as 5.10.1, first read perl5120delta,
       which describes differences between 5.10.0 and 5.12.0, as well as perl5121delta, which
       describes earlier changes in the 5.12 stable release series.

Incompatible Changes
       There are no changes intentionally incompatible with 5.12.1. If any exist, they are bugs and
       reports are welcome.

Core Enhancements
       Other than the bug fixes listed below, there should be no user-visible changes to the core
       language in this release.

Modules and Pragmata
   New Modules and Pragmata
       This release does not introduce any new modules or pragmata.

   Pragmata Changes
       In the previous release, "no VERSION;" statements triggered a bug which could cause feature
       bundles to be loaded and strict mode to be enabled unintentionally.

   Updated Modules
       "Carp"
           Upgraded from version 1.16 to 1.17.

           Carp  now  detects  incomplete  caller()  overrides  and avoids using bogus @DB::args. To
           provide backtraces, Carp relies on particular behaviour of the caller built-in. Carp  now
           detects if other code has overridden this with an incomplete implementation, and modifies
           its  backtrace  accordingly. Previously incomplete overrides would cause incorrect values
           in backtraces (best case), or obscure fatal errors (worst case)

           This fixes certain cases of "Bizarre copy of ARRAY" caused by modules overriding caller()
           incorrectly.

       "CPANPLUS"
           A patch to cpanp-run-perl has been backported from  CPANPLUS  0.9004.  This  resolves  RT
           #55964     <http://rt.cpan.org/Public/Bug/Display.html?id=55964>     and     RT    #57106
           <http://rt.cpan.org/Public/Bug/Display.html?id=57106>, both of which related to  failures
           to install distributions that use "Module::Install::DSL".

       "File::Glob"
           A   regression  which  caused  a  failure  to  find  "CORE::GLOBAL::glob"  after  loading
           "File::Glob" to crash has been fixed.  Now, it correctly falls back to external  globbing
           via "pp_glob".

       "File::Copy"
           "File::Copy::copy(FILE, DIR)" is now documented.

       "File::Spec"
           Upgraded from version 3.31 to 3.31_01.

           Several  portability fixes were made in "File::Spec::VMS": a colon is now recognized as a
           delimiter in  native  filespecs;  caret-escaped  delimiters  are  recognized  for  better
           handling  of  extended  filespecs;  catpath()  returns an empty directory rather than the
           current directory if the input directory name is empty; abs2rel() properly handles  Unix-
           style input.

Utility Changes
       •   perlbug now always gives the reporter a chance to change the email address it guesses for
           them.

       •   perlbug  should  no  longer  warn about uninitialized values when using the "-d" and "-v"
           options.

Changes to Existing Documentation
       •   The  existing  policy  on  backward-compatibility  and  deprecation  has  been  added  to
           perlpolicy, along with definitions of terms like deprecation.

       •   "srand" in perlfunc's usage has been clarified.

       •   The  entry  for  "die" in perlfunc was reorganized to emphasize its role in the exception
           mechanism.

       •   Perl's INSTALL file has been clarified to explicitly  state  that  Perl  requires  a  C89
           compliant ANSI C Compiler.

       •   IO::Socket's getsockopt() and setsockopt() have been documented.

       •   alarm()'s inability to interrupt blocking IO on Windows has been documented.

       •   Math::TrulyRandom  hasn't  been  updated since 1996 and has been removed as a recommended
           solution for random number generation.

       •   perlrun has been updated to clarify the behaviour of octal flags to perl.

       •   To ease user confusion, $# and $*, two special variables that  were  removed  in  earlier
           versions of Perl have been documented.

       •   The  version of perlfaq shipped with the Perl core has been updated from the official FAQ
           version, which is now maintained in the "briandfoy/perlfaq" branch of the Perl repository
           at <git://perl5.git.perl.org/perl.git>.

Installation and Configuration Improvements
   Configuration improvements
       •   The "d_u32align" configuration probe on ARM has been fixed.

   Compilation improvements
       •   An ""incompatible operand types"" error in ternary expressions when building with "clang"
           has been fixed.

       •   Perl now skips setuid "File::Copy" tests on  partitions  it  detects  to  be  mounted  as
           "nosuid".

Selected Bug Fixes
       •   A possible segfault in the "T_PRTOBJ" default typemap has been fixed.

       •   A possible memory leak when using caller() to set @DB::args has been fixed.

       •   Several memory leaks when loading XS modules were fixed.

       •   unpack()  now  handles  scalar  context  correctly  for %32H and %32u, fixing a potential
           crash.  split() would crash because the third  item  on  the  stack  wasn't  the  regular
           expression  it  expected.  "unpack("%2H", ...)" would return both the unpacked result and
           the  checksum   on   the   stack,   as   would   "unpack("%2u",   ...)".    [GH   #10257]
           <https://github.com/Perl/perl5/issues/10257>

       •   Perl  now  avoids using memory after calling free() in pp_require when there are CODEREFs
           in @INC.

       •   A bug that could cause ""Unknown  error""  messages  when  ""call_sv(code,  G_EVAL)""  is
           called from an XS destructor has been fixed.

       •   The implementation of the "open $fh, '>' \$buffer" feature now supports get/set magic and
           thus tied buffers correctly.

       •   The  "pp_getc",  "pp_tell",  and  "pp_eof"  opcodes  now make room on the stack for their
           return values in cases where no argument was passed in.

       •   When matching unicode strings under  some  conditions  inappropriate  backtracking  would
           result  in a "Malformed UTF-8 character (fatal)" error. This should no longer occur.  See
           [GH #10434] <https://github.com/Perl/perl5/issues/10434>

Platform Specific Notes
   AIX
       •   README.aix has been updated with information about the XL C/C++ V11 compiler suite.

   Windows
       •   When building Perl with the mingw64 x64 cross-compiler  "incpath",  "libpth",  "ldflags",
           "lddlflags"  and  "ldflags_nolargefiles" values in Config.pm and Config_heavy.pl were not
           previously being  set  correctly  because,  with  that  compiler,  the  include  and  lib
           directories are not immediately below "$(CCHOME)".

   VMS
       •   git_version.h is now installed on VMS. This was an oversight in v5.12.0 which caused some
           extensions to fail to build.

       •   Several memory leaks in stat() have been fixed.

       •   A memory leak in Perl_rename() due to a double allocation has been fixed.

       •   A memory leak in vms_fid_to_name() (used by realpath() and realname()) has been fixed.

Acknowledgements
       Perl  5.12.2  represents  approximately  three  months  of  development since Perl 5.12.1 and
       contains approximately 2,000 lines of changes across 100 files from 36 authors.

       Perl continues to flourish into its third decade thanks to a vibrant community of  users  and
       developers.   The following people are known to have contributed the improvements that became
       Perl 5.12.2:

       Abigail, Ævar Arnfjörð Bjarmason, Ben Morrow, brian d foy, Brian Phillips, Chas. Owens, Chris
       'BinGOs' Williams, Chris Williams, Craig A.  Berry,  Curtis  Jewell,  Dan  Dascalescu,  David
       Golden,  David  Mitchell, Father Chrysostomos, Florian Ragwitz, George Greer, H.Merijn Brand,
       Jan Dubois, Jesse Vincent, Jim Cromie, Karl Williamson, Lars Dɪᴇᴄᴋᴏᴡ 迪拉斯, Leon Brocard,  Maik
       Hentsche,  Matt S Trout, Nicholas Clark, Rafael Garcia-Suarez, Rainer Tammer, Ricardo Signes,
       Salvador Ortiz Garcia, Sisyphus, Slaven Rezic, Steffen Mueller, Tony Cook,  Vincent  Pit  and
       Yves Orton.

Reporting Bugs
       If  you  find  what  you  think is a bug, you might check the articles recently posted to the
       comp.lang.perl.misc newsgroup and the perl  bug  database  at  http://rt.perl.org/perlbug/  .
       There may also be information at http://www.perl.org/ , the Perl Home Page.

       If  you believe you have an unreported bug, please run the perlbug program included with your
       release.  Be sure to trim your bug down to a tiny but sufficient test case.  Your bug report,
       along with the output of "perl -V", will be sent off to perlbug AT perl.org to  be  analysed  by
       the Perl porting team.

       If  the  bug you are reporting has security implications, which make it inappropriate to send
       to a publicly archived mailing list, then please send it  to  perl5-security-report AT perl.org.
       This  points  to  a  closed subscription unarchived mailing list, which includes all the core
       committers, who will be able to help assess the impact of issues, figure  out  a  resolution,
       and  help  co-ordinate  the  release  of  patches  to  mitigate or fix the problem across all
       platforms on which Perl is supported. Please only use this address for security issues in the
       Perl core, not for modules independently distributed on CPAN.

SEE ALSO
       The Changes file for an explanation of how to view exhaustive details on what changed.

       The INSTALL file for how to build Perl.

       The README file for general stuff.

       The Artistic and Copying files for copyright information.

perl v5.38.2                                 2026-08-18                             PERL5122DELTA(1)