{ "mode": "man", "parameter": "PERL5121DELTA", "section": "1", "url": "https://www.chedong.com/phpMan.php/man/PERL5121DELTA/1/json", "generated": "2026-10-06T14:22:24Z", "sections": { "NAME": { "content": "perl5121delta - what is new for perl v5.12.1\n", "subsections": [] }, "DESCRIPTION": { "content": "This document describes differences between the 5.12.0 release and the 5.12.1 release.\n\nIf you are upgrading from an earlier release such as 5.10.1, first read perl5120delta, which\ndescribes differences between 5.10.0 and 5.12.0.\n", "subsections": [] }, "Incompatible Changes": { "content": "There are no changes intentionally incompatible with 5.12.0. If any incompatibilities with\n5.12.0 exist, they are bugs. Please report them.\n", "subsections": [] }, "Core Enhancements": { "content": "Other than the bug fixes listed below, there should be no user-visible changes to the core\nlanguage in this release.\n", "subsections": [] }, "Modules and Pragmata": { "content": "", "subsections": [ { "name": "Pragmata Changes", "content": "• We fixed exporting of \"isstrict\" and \"islax\" from version.\n\nThese were being exported with a wrapper that treated them as method calls, which caused\nthem to fail. They are just functions, are documented as such, and should never be\nsubclassed, so this patch just exports them directly as functions without the wrapper.\n" }, { "name": "Updated Modules", "content": "• We upgraded CGI to version 3.49 to incorporate fixes for regressions introduced in the\nrelease we shipped with Perl 5.12.0.\n\n• We upgraded Pod::Simple to version 3.14 to get an improvement to \\C\\<\\< \\>\\> parsing.\n\n• We made a small fix to the CPANPLUS test suite to fix an occasional spurious test\nfailure.\n\n• We upgraded Safe to version 2.27 to wrap coderefs returned by reval() and rdo().\n" } ] }, "Changes to Existing Documentation": { "content": "• We added the new maintenance release policy to perlpolicy\n\n• We've clarified the multiple-angle-bracket construct in the spec for POD in perlpodspec\n\n• We added a missing explanation for a warning about \":=\" to perldiag\n\n• We removed a false claim in perlunitut that all text strings are Unicode strings in Perl.\n\n• We updated the GitHub mirror link in perlrepository to mirrors/perl, not github/perl\n\n• We fixed a minor error in perl5114delta.\n\n• We replaced a mention of the now-obsolete Switch with given/when.\n\n• We improved documentation about $sitelibexp/sitecustomize.pl in perlrun.\n\n• We corrected perlmodlib which had unintentionally omitted a number of modules.\n\n• We updated the documentation for 'require' in perlfunc relating to putting Perl code in\n@INC.\n\n• We reinstated some erroneously-removed documentation about quotemeta in perlfunc.\n\n• We fixed an a2p example in perlutil.\n\n• We filled in a blank in perlport with the release date of Perl 5.12.\n\n• We fixed broken links in a number of perldelta files.\n\n• The documentation for Carp incorrectly stated that the $Carp::Verbose variable makes\ncluck generate stack backtraces.\n\n• We fixed a number of typos in Pod::Functions\n\n• We improved documentation of case-changing functions in perlfunc\n\n• We corrected perlgpl to contain the correct version of the GNU General Public License.\n", "subsections": [] }, "Testing": { "content": "", "subsections": [ { "name": "Testing Improvements", "content": "• t/op/sselect.t is now less prone to clock jitter during timing checks on Windows.\n\nsleep() time on Win32 may be rounded down to multiple of the clock tick interval.\n\n• lib/blib.t and lib/locale.t: Fixes for test failures on Darwin/PPC\n\n• perl5db.t: Fix for test failures when \"Term::ReadLine::Gnu\" is installed.\n" } ] }, "Installation and Configuration Improvements": { "content": "", "subsections": [ { "name": "Configuration improvements", "content": "• We updated INSTALL with notes about how to deal with broken dbm.h on OpenSUSE (and\npossibly other platforms)\n\nBug Fixes\n• A bug in how we process filetest operations could cause a segfault. Filetests don't\nalways expect an op on the stack, so we now use TOPs only if we're sure that we're not\nstat'ing the filehandle. This is indicated by OPfKIDS (as checked in ckftst).\n\nSee also: \n\n• When deparsing a nextstate op that has both a change of package (relative to the previous\nnextstate) and a label, the package declaration is now emitted first, because it is\nsyntactically impermissible for a label to prefix a package declaration.\n\n• XSUB.h now correctly redefines fgets under PERLIMPLICITSYS\n\nSee also: \n\n• utf8::isutf8 now respects GMAGIC (e.g. $1)\n\n• XS code using fputc() or fputs(): on Windows could cause an error due to their arguments\nbeing swapped.\n\nSee also: \n\n• We fixed a small bug in lexstuffpvn() that caused spurious syntax errors in an obscure\nsituation. It happened when stuffing was performed on the last line of a file and the\nline ended with a statement that lacked a terminating semicolon.\n\nSee also: \n\n• We fixed a bug that could cause \\N{} constructs followed by a single . to be parsed\nincorrectly.\n\nSee also: \n\n• We fixed a bug that caused when(scalar) without an argument not to be treated as a syntax\nerror.\n\nSee also: \n\n• We fixed a regression in the handling of labels immediately before string evals that was\nintroduced in Perl 5.12.0.\n\nSee also: \n\n• We fixed a regression in case-insensitive matching of folded characters in regular\nexpressions introduced in Perl 5.10.1.\n\nSee also: \n" } ] }, "Platform Specific Notes": { "content": "HP-UX\n• Perl now allows -Duse64bitint without promoting to use64bitall on HP-UX\n\nAIX\n• Perl now builds on AIX 4.2\n\nThe changes required work around AIX 4.2s' lack of support for IPv6, and limited support\nfor POSIX sigaction().\n", "subsections": [ { "name": "FreeBSD 7", "content": "• FreeBSD 7 no longer contains /usr/bin/objformat. At build time, Perl now skips the\nobjformat check for versions 7 and higher and assumes ELF.\n\nVMS\n• It's now possible to build extensions on older (pre 7.3-2) VMS systems.\n\nDCL symbol length was limited to 1K up until about seven years or so ago, but there was\nno particularly deep reason to prevent those older systems from configuring and building\nPerl.\n\n• We fixed the previously-broken \"-Uuseperlio\" build on VMS.\n\nWe were checking a variable that doesn't exist in the non-default case of disabling\nperlio. Now we only look at it when it exists.\n\n• We fixed the -Uuseperlio command-line option in configure.com.\n\nFormerly it only worked if you went through all the questions interactively and\nexplicitly answered no.\n" } ] }, "Known Problems": { "content": "• \"List::Util::first\" misbehaves in the presence of a lexical $ (typically introduced by\n\"my $\" or implicitly by \"given\"). The variable which gets set for each iteration is the\npackage variable $, not the lexical $.\n\nA similar issue may occur in other modules that provide functions which take a block as\ntheir first argument, like\n\nfoo { ... $ ...} list\n\nSee also: \n\n• \"Module::Load::Conditional\" and \"version\" have an unfortunate interaction which can cause\n\"CPANPLUS\" to crash when it encounters an unparseable version string. Upgrading to\n\"CPANPLUS\" 0.9004 or \"Module::Load::Conditional\" 0.38 from CPAN will resolve this issue.\n", "subsections": [] }, "Acknowledgements": { "content": "Perl 5.12.1 represents approximately four weeks of development since Perl 5.12.0 and contains\napproximately 4,000 lines of changes across 142 files from 28 authors.\n\nPerl continues to flourish into its third decade thanks to a vibrant community of users and\ndevelopers. The following people are known to have contributed the improvements that became\nPerl 5.12.1:\n\nÆvar Arnfjörð Bjarmason, Chris Williams, chromatic, Craig A. Berry, David Golden, Father\nChrysostomos, Florian Ragwitz, Frank Wiegand, Gene Sullivan, Goro Fuji, H.Merijn Brand, James\nE Keenan, Jan Dubois, Jesse Vincent, Josh ben Jore, Karl Williamson, Leon Brocard, Michael\nSchwern, Nga Tang Chan, Nicholas Clark, Niko Tyni, Philippe Bruhat, Rafael Garcia-Suarez,\nRicardo Signes, Steffen Mueller, Todd Rinaldo, Vincent Pit and Zefram.\n", "subsections": [] }, "Reporting Bugs": { "content": "If you find what you think is a bug, you might check the articles recently posted to the\ncomp.lang.perl.misc newsgroup and the perl bug database at http://rt.perl.org/perlbug/ .\nThere may also be information at http://www.perl.org/ , the Perl Home Page.\n\nIf you believe you have an unreported bug, please run the perlbug program included with your\nrelease. Be sure to trim your bug down to a tiny but sufficient test case. Your bug report,\nalong with the output of \"perl -V\", will be sent off to perlbug@perl.org to be analysed by\nthe Perl porting team.\n\nIf the bug you are reporting has security implications, which make it inappropriate to send\nto a publicly archived mailing list, then please send it to perl5-security-report@perl.org.\nThis points to a closed subscription unarchived mailing list, which includes all the core\ncommitters, who will be able to help assess the impact of issues, figure out a resolution,\nand help co-ordinate the release of patches to mitigate or fix the problem across all\nplatforms on which Perl is supported. Please only use this address for security issues in the\nPerl core, not for modules independently distributed on CPAN.\n", "subsections": [] }, "SEE ALSO": { "content": "The Changes file for an explanation of how to view exhaustive details on what changed.\n\nThe INSTALL file for how to build Perl.\n\nThe README file for general stuff.\n\nThe Artistic and Copying files for copyright information.\n\nperl v5.38.2 2026-08-18 PERL5121DELTA(1)", "subsections": [] } }, "summary": "perl5121delta - what is new for perl v5.12.1", "flags": [], "examples": [], "see_also": [] }