PERL5202DELTA(1)

🦋 PERL5202DELTA(1) 🦋

Perl Programmers Reference Guide

✨ NAME ✨

perl5202delta — what is new for perl v5.20.2 💖

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🌸 DESCRIPTION 🌸

okay so bestie, this doc is literally just the tea on what changed between the 5.20.1 release and the 5.20.2 release. that's it. that's the whole vibe. 💅

and if you're jumping in from something even older, like 5.20.0? no worries, just read perl5201delta first, because that one covers the 5.20.0 → 5.20.1 glow-up. 📖✨

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💀 Incompatible Changes 💀

none. zero. nada. there are no changes intentionally incompatible with 5.20.1. like, if you find one, that's a bug, not a feature, and we would very much love for you to submit a report. check out "Reporting Bugs" below for the deets. 🐛🫶

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🎀 Modules and Pragmata 🎀

💅 Updated Modules and Pragmata

• attributes — upgraded from version 0.22 to 0.23.

the usage of memEQs in the XS has been corrected. [GH #14072] <https://github.com/Perl/perl5/issues/14072>

• Data::Dumper — upgraded from version 2.151 to 2.151_01.

fixes CVE-2014-4330 by adding a configuration variable/option to limit recursion when dumping deep data structures. security girlie behavior, we love to see it 🔥

• Errno — upgraded from version 1.20_03 to 1.20_05.

warnings when building the XS on Windows with the Visual C++ compiler are now avoided. no more yapping from the compiler 😌

• feature — upgraded from version 1.36 to 1.36_01.

the postderef feature has now been documented. this feature was actually added in Perl 5.20.0 but was accidentally omitted from the feature documentation until now. not me forgetting to write it down for a whole release 🙈

• IO::Socket — upgraded from version 1.37 to 1.38.

document the limitations of the connected() method. [GH #14199] <https://github.com/Perl/perl5/issues/14199>

• Module::CoreList — upgraded from version 5.020001 to 5.20150214.

the list of Perl versions covered has been updated. ⭐

• PathTools — upgraded from version 3.48 to 3.48_01.

a warning from the gcc compiler is now avoided when building the XS. silence is golden 🤫

• PerlIO::scalar — upgraded from version 0.18 to 0.18_01.

reading from a position well past the end of the scalar now correctly returns end of file. [GH #14342] <https://github.com/Perl/perl5/issues/14342>

seeking to a negative position still fails, but no longer leaves the file position set to a negation location.

eof() on a PerlIO::scalar handle now properly returns true when the file position is past the 2GB mark on 32-bit systems. 32-bit besties, this one's for you 🫶

• Storable — upgraded from version 2.49 to 2.49_01.

minor grammatical change to the documentation only. just a lil grammar fix, no biggie ✍️

• VMS::DCLsym — upgraded from version 1.05 to 1.05_01.

minor formatting change to the documentation only. ✨

• VMS::Stdio — upgraded from version 2.4 to 2.41.

minor formatting change to the documentation only. ✨

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📚 Documentation 📚

🌈 New Documentation

perlunicook

this document, by Tom Christiansen, provides examples of handling Unicode in Perl. iconic, honestly 🧚

💜 Changes to Existing Documentation

perlexperiment

• added reference to subroutine signatures. this feature was actually added in Perl 5.20.0 but was accidentally omitted from the experimental feature documentation until now. 🙈

perlpolic... wait no — perlpolicy 💅

• the process whereby features may graduate from experimental status has now been formally documented. glow-up pipeline, documented 👑

perlsyn

• an ambiguity in the documentation of the ellipsis statement has been corrected. [GH #14054] <https://github.com/Perl/perl5/issues/14054>

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🩺 Diagnostics 🩺

the following additions or changes have been made to diagnostic output, including warnings and fatal error messages. for the complete list of diagnostic messages, see perldiag. 📋

🔍 Changes to Existing Diagnostics

• Bad symbol for scalar is now documented. this error is not new, but was not previously documented here. it was always there, just undocumented, living its mystery era 💀
• Missing right brace on \N{} is now documented. this error is not new, but was not previously documented here. 💀

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🧪 Testing 🧪

• the test script re/rt122747.t has been added to verify that [GH #14081] <https://github.com/Perl/perl5/issues/14081> remains fixed. regression test staying on guard duty 🫡

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🖥️ Platform Support 🖥️

🦋 Regained Platforms

IRIX and Tru64 platforms are working again. (some make test failures remain.) they're back, mostly, kind of, we're working on it 😭

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🔧 Selected Bug Fixes 🔧

• AIX now sets the length in getsockopt correctly. [GH #13484] <https://github.com/Perl/perl5/issues/13484>, [cpan #91183] <https://rt.cpan.org/Ticket/Display.html?id=91183>, [cpan #85570] <https://rt.cpan.org/Ticket/Display.html?id=85570>
• in Perl 5.20.0, $^N accidentally had the internal UTF8 flag turned off if accessed from a code block within a regular expression, effectively UTF8-encoding the value. this has been fixed. [GH #14211] <https://github.com/Perl/perl5/issues/14211>
• various cases where the name of a sub is used (autoload, overloading, error messages) used to crash for lexical subs, but have been fixed. no more crashing, just vibing 😌
• an assertion failure when parsing sort with debugging enabled has been fixed. [GH #14087] <https://github.com/Perl/perl5/issues/14087>
• loading UTF8 tables during a regular expression match could cause assertion failures under debugging builds if the previous match used the very same regular expression. [GH #14081] <https://github.com/Perl/perl5/issues/14081>
• due to a mistake in the string-copying logic, copying the value of a state variable could instead steal the value and undefine the variable. this bug, introduced in Perl 5.20, would happen mostly for long strings (1250 chars or more), but could happen for any strings under builds with copy-on-write disabled. [GH #14175] <https://github.com/Perl/perl5/issues/14175>
• fixed a bug that could cause perl to execute an infinite loop during compilation. [GH #14165] <https://github.com/Perl/perl5/issues/14165> infinite loop in the compiler, truly the final boss 💀
• on Win32, restoring in a child pseudo-process a variable that was local()ed in a parent pseudo-process before the fork happened caused memory corruption and a crash in the child pseudo-process (and therefore OS process). [GH #8641] <https://github.com/Perl/perl5/issues/8641>
• tainted constants evaluated at compile time no longer cause unrelated statements to become tainted. [GH #14059] <https://github.com/Perl/perl5/issues/14059>
• calling write on a format with a ^** field could produce a panic in sv_chop() if there were insufficient arguments or if the variable used to fill the field was empty. [GH #14255] <https://github.com/Perl/perl5/issues/14255>
• in Perl 5.20.0, sort CORE::fake where 'fake' is anything other than a keyword started chopping off the last 6 characters and treating the result as a sort sub name. the previous behaviour of treating CORE::fake as a sort sub name has been restored. [GH #14323] <https://github.com/Perl/perl5/issues/14323>
• a bug in regular expression patterns that could lead to segfaults and other crashes has been fixed. this occurred only in patterns compiled with /i, while taking into account the current POSIX locale (this usually means they have to be compiled within the scope of use locale), and there must be a string of at least 128 consecutive bytes to match. [GH #14389] <https://github.com/Perl/perl5/issues/14389>
• qr/@array(?{block})/ no longer dies with Bizarre copy of ARRAY. [GH #14292] <https://github.com/Perl/perl5/issues/14292>
• gmtime no longer crashes with not-a-number values. [GH #14365] <https://github.com/Perl/perl5/issues/14365>
• certain syntax errors in substitutions, such as s/${<>{})//, would crash, and had done so since Perl 5.10. (in some cases the crash did not start happening until Perl 5.16.) the crash has, of course, been fixed. [GH #14391] <https://github.com/Perl/perl5/issues/14391> "of course" the shade of it all 💅
• a memory leak in some regular expressions, introduced in Perl 5.20.1, has been fixed. [GH #14236] <https://github.com/Perl/perl5/issues/14236>
• formline("@...", "a"); would crash. the FF_CHECKNL case in pp_formline() didn't set the pointer used to mark the chop position, which led to the FF_MORE case crashing with a segmentation fault. this has been fixed. [GH #14388] <https://github.com/Perl/perl5/issues/14388> [GH #14425] <https://github.com/Perl/perl5/issues/14425>
• a possible buffer overrun and crash when parsing a literal pattern during regular expression compilation has been fixed. [GH #14416] <https://github.com/Perl/perl5/issues/14416>

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⚠️ Known Problems ⚠️

• it is a known bug that lexical subroutines cannot be used as the SUBNAME argument to sort. this will be fixed in a future version of Perl. not fixed yet bestie, patience 🫶

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📜 Errata From Previous Releases 📜

• a regression has been fixed that was introduced in Perl 5.20.0 (fixed in Perl 5.20.1 as well as here) in which a UTF-8 encoded regular expression pattern that contains a single ASCII lowercase letter does not match its uppercase counterpart. [GH #14051] <https://github.com/Perl/perl5/issues/14051>

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🫶 Acknowledgements 🫶

Perl 5.20.2 represents approximately 5 months of development since Perl 5.20.1 and contains approximately 6,300 lines of changes across 170 files from 34 authors. that's a whole lot of slay 💖

excluding auto-generated files, documentation and release tools, there were approximately 1,900 lines of changes to 80 .pm, .t, .c and .h files.

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 5.20.2:

Aaron Crane, Abigail, Andreas Voegele, Andy Dougherty, Anthony Heading, Aristotle Pagaltzis, Chris 'BinGOs' Williams, Craig A. Berry, Daniel Dragan, Doug Bell, Ed J, Father Chrysostomos, Glenn D. Golden, H.Merijn Brand, Hugo van der Sanden, James E Keenan, Jarkko Hietaniemi, Jim Cromie, Karen Etheridge, Karl Williamson, kmx, Matthew Horsfall, Max Maischein, Peter Martini, Rafael Garcia-Suarez, Ricardo Signes, Shlomi Fish, Slaven Rezic, Steffen Müller, Steve Hay, Tadeusz Sośnierz, Tony Cook, Yves Orton, Ævar Arnfjörð Bjarmason. 👑

the list above is almost certainly incomplete as it is automatically generated from version control history. in particular, it does not include the names of the (very much appreciated) contributors who reported issues to the Perl bug tracker. bug reporters, you are seen and you are loved 🫶

many of the changes included in this version originated in the CPAN modules included in Perl's core. we're grateful to the entire CPAN community for helping Perl to flourish. 🌸

for a more complete list of all of Perl's historical contributors, please see the AUTHORS file in the Perl source distribution. 📄

🐛 Reporting Bugs 🐛

okay bestie so if you think you found a bug, first things first — don't just scream into the void 💀 do a lil detective work. Go check the articles that got posted recently to the comp.lang.perl.misc newsgroup, and also the perl bug database over at https://rt.perl.org/ . There might also be info waiting for you at http://www.perl.org/ , aka the Perl Home Page. Like, do your research, queen 👑

But if you genuinely believe you've got an unreported bug? Then it's your moment, main character energy ✨ run the perlbug program that ships with your release. And please — trim your bug down to a tiny but sufficient test case. Tiny. But sufficient. Both. We're not reading your entire 4,000-line script, we're not built for that 😭

Your bug report, plus the output of perl -V, gets sent off to perlbug@perl.org where the Perl porting team will analyse it. So yeah, they're the ones reading it. Be nice to them 🫶

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SECURITY BESTIES, LISTEN UP 🚨 if the bug you're reporting has security implications — which makes it straight up inappropriate to send to a publicly archived mailing list — then send it to perl5-security-report@perl.org instead. Do not just yeet it into the public tracker, that's the whole point.

That address points to a closed subscription unarchived mailing list, and it 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. Iconic teamwork, honestly 🌈

⚠️ Please only use that address for security issues in the Perl core — not for modules independently distributed on CPAN. Those are somebody else's problem bestie, respectfully 💅

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🌸 SEE ALSO 🌸

• 📜 The Changes file — for an explanation of how to view exhaustive details on what changed. Exhaustive. Like, every last crumb.
• 🛠️ The INSTALL file — for how to build Perl.
• 📖 The README file — for general stuff. The vibes file, basically.
• ⚖️ The Artistic and Copying files — for copyright information.

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and that's a wrap on this one, bestie 🎀 this was perl v5.42.3, dated 2026-08-03, filed under PERL5202DELTA(1) ✨ go forth and read your deltas, you absolute legend 👑💖