PERL5121DELTA(1perl)

📦

version 5.44.0 · 2 versions

5.44.0 · arch rolling (latest)
5.42.3 · arch rolling

💖 PERL5121DELTA — what's new for perl v5.12.1 💖

okay bestie, gather round 🫶 this is the PERL5121DELTA(1perl) page — the full tea on the 5.12.1 drop. it's a maintenance release, so it's giving "quiet luxury" more than "main character chaos", but every single detail matters. let's go. ✨

🌸 NAME 🌸

perl5121delta — what is new for perl v5.12.1 💅

🦋 DESCRIPTION 🦋

This doc spills the differences between the 5.12.0 release and the 5.12.1 release. no cap.

If you're upgrading from something older like 5.10.1, first go read perl5120delta, which covers everything between 5.10.0 and 5.12.0. skipping it is not the move, fr fr.

💀 Incompatible Changes 💀

There are no changes intentionally incompatible with 5.12.0. literally none. And if any incompatibilities with 5.12.0 do exist? They're bugs. like, actual bugs. please report them. 🙈

✨ Core Enhancements ✨

Other than the bug fixes listed below, there should be no user-visible changes to the core language in this release. so if you were hoping for a glow-up, this is more of a skincare-routine release: maintenance, not transformation. 🧖

🎀 Modules and Pragmata 🎀

💅 Pragmata Changes

We fixed exporting of is_strict and is_lax from version.

These were being exported with a wrapper that treated them as method calls, which caused them to fail. 😭 They are just functions, they are documented as functions, and they should never be subclassed — so this patch just exports them directly as functions, no wrapper, no drama. periodt.

⭐ Updated Modules

We upgraded CGI to version 3.49 to incorporate fixes for regressions introduced in the release we shipped with Perl 5.12.0. (oops, but make it fixed 🫶)
We upgraded Pod::Simple to version 3.14 to get an improvement to \C\<\< \>\> parsing.
We made a small fix to the CPANPLUS test suite to fix an occasional spurious test failure. fake failures are NOT invited to the function. 🚫
We upgraded Safe to version 2.27 to wrap coderefs returned by reval() and rdo().

📚 Changes to Existing Documentation 📚

We added the new maintenance release policy to perlpolicy
We've clarified the multiple-angle-bracket construct in the spec for POD in perlpodspec
We added a missing explanation for a warning about := to perldiag
We removed a false claim in perlunitut that all text strings are Unicode strings in Perl. (ngl that claim was simply not it)
We updated the GitHub mirror link in perlrepository to mirrors/perl, not github/perl
We fixed a minor error in perl5114delta.
We replaced a mention of the now-obsolete Switch with given/when.
We improved documentation about $sitelibexp/sitecustomize.pl in perlrun.
We corrected perlmodlib which had unintentionally omitted a number of modules. we were lowkey gatekeeping modules, unintentionally. 🙈
We updated the documentation for require in perlfunc relating to putting Perl code in @INC.
We reinstated some erroneously-removed documentation about quotemeta in perlfunc.
We fixed an a2p example in perlutil.
We filled in a blank in perlport with the release date of Perl 5.12.
We fixed broken links in a number of perldelta files. links that 404 are canceled, bestie.
The documentation for Carp incorrectly stated that the $Carp::Verbose variable makes cluck generate stack backtraces.
We fixed a number of typos in Pod::Functions
We improved documentation of case-changing functions in perlfunc
We corrected perlgpl to contain the correct version of the GNU General Public License.

🧪 Testing 🧪

🔥 Testing Improvements

t/op/sselect.t is now less prone to clock jitter during timing checks on Windows.

sleep() time on Win32 may be rounded down to multiple of the clock tick interval. so if the test was acting up, it wasn't the test's fault, it was the clock's.

lib/blib.t and lib/locale.t: Fixes for test failures on Darwin/PPC
perl5db.t: Fix for test failures when Term::ReadLine::Gnu is installed.

🛠️ Installation and Configuration Improvements 🛠️

🌈 Configuration improvements

We updated INSTALL with notes about how to deal with broken dbm.h on OpenSUSE (and possibly other platforms)

🐛 Bug Fixes 🐛

A bug in how we process filetest operations could cause a segfault. Filetests don't always expect an op on the stack, so we now use TOPs only if we're sure that we're not stat'ing the _ filehandle. This is indicated by OPf_KIDS (as checked in ck_ftst).

When deparsing a nextstate op that has both a change of package (relative to the previous nextstate) and a label, the package declaration is now emitted first, because it is syntactically impermissible for a label to prefix a package declaration.
XSUB.h now correctly redefines fgets under PERL_IMPLICIT_SYS

utf8::is_utf8 now respects GMAGIC (e.g. $1)
XS code using fputc() or fputs(): on Windows could cause an error due to their arguments being swapped. 💀

We fixed a small bug in lex_stuff_pvn() that caused spurious syntax errors in an obscure situation. It happened when stuffing was performed on the last line of a file and the line ended with a statement that lacked a terminating semicolon.

We fixed a bug that could cause \N{} constructs followed by a single . to be parsed incorrectly.

We fixed a bug that caused when(scalar) without an argument not to be treated as a syntax error.

We fixed a regression in the handling of labels immediately before string evals that was introduced in Perl 5.12.0.

We fixed a regression in case-insensitive matching of folded characters in regular expressions introduced in Perl 5.10.1.

👑 Platform Specific Notes 👑

🍓 HP-UX

Perl now allows -Duse64bitint without promoting to use64bitall on HP-UX

🧚 AIX

Perl now builds on AIX 4.2

The changes required work around AIX 4.2s' lack of support for IPv6, and limited support for POSIX sigaction().

💜 FreeBSD 7

FreeBSD 7 no longer contains /usr/bin/objformat. At build time, Perl now skips the objformat check for versions 7 and higher and assumes ELF.

🌊 VMS

It's now possible to build extensions on older (pre 7.3-2) VMS systems.

DCL symbol length was limited to 1K up until about seven years or so ago, but there was no particularly deep reason to prevent those older systems from configuring and building Perl. respect the elders. 🫡

We fixed the previously-broken -Uuseperlio build on VMS.

We were checking a variable that doesn't exist in the non-default case of disabling perlio. Now we only look at it when it exists. (checking for something that isn't there is giving ghost hunting 👻)

We fixed the -Uuseperlio command-line option in configure.com.

Formerly it only worked if you went through all the questions interactively and explicitly answered no.

⚠️ Known Problems ⚠️

List::Util::first misbehaves in the presence of a lexical $_ (typically introduced by my $_ or implicitly by given). The variable which gets set for each iteration is the package variable $_, not the lexical $_.

A similar issue may occur in other modules that provide functions which take a block as their first argument, like

    foo { ... $_ ...} list

Module::Load::Conditional and version have an unfortunate interaction which can cause CPANPLUS to crash when it encounters an unparseable version string. Upgrading to CPANPLUS 0.9004 or Module::Load::Conditional 0.38 from CPAN will resolve this issue. 🔧

💖 Acknowledgements 💖

Perl 5.12.1 represents approximately four weeks of development since Perl 5.12.0 and contains approximately 4,000 lines of changes across 142 files from 28 authors. that's a whole group project and everybody actually did their part?? iconic. 🌟

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 5.12.1:

Ævar Arnfjörð Bjarmason, Chris Williams, chromatic, Craig A. Berry, David Golden, Father Chrysostomos, Florian Ragwitz, Frank Wiegand, Gene Sullivan, Goro Fuji, H.Merijn Brand, James E Keenan, Jan Dubois, Jesse Vincent, Josh ben Jore, Karl Williamson, Leon Brocard, Michael Schwern, Nga Tang Chan, Nicholas Clark, Niko Tyni, Philippe Bruhat, Rafael Garcia-Suarez, Ricardo Signes, Steffen Mueller, Todd Rinaldo, Vincent Pit and Zefram. 👑

🐞 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@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@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. 🔒 no snitching to the wrong inbox bestie

👀 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.

okay that's the whole thing, you're caught up bestie 💅 this was perl v5.44.0, dated 2026-10-17, and it's the PERL5121DELTA(1perl) page — read it, love it, go upgrade responsibly. mwah 🩷🦋✨

📦 where this page comes from

arch rolling: perl 5.44.0-1 · Artistic-1.0-Perl AND GPL-1.0-or-later
💖 girlified by deepseek-ai/DeepSeek-V4.1-Flash on 2026-11-03: a language model's rewrite of the original, under its terms