++ed by:

177 PAUSE users
171 non-PAUSE users.

Chris Williams
and 1 contributors


perl5272delta - what is new for perl v5.27.2


This document describes differences between the 5.27.1 release and the 5.27.2 release.

If you are upgrading from an earlier release such as 5.27.0, first read perl5271delta, which describes differences between 5.27.0 and 5.27.1.

Core Enhancements

Unicode 10.0 is supported

A list of changes is at http://www.unicode.org/versions/Unicode10.0.0.

Modules and Pragmata

Updated Modules and Pragmata

  • arybase has been upgraded from version 0.12 to 0.13.

  • Carp has been upgraded from version 1.42 to 1.43.

  • Encode has been upgraded from version 2.88 to 2.92.

  • encoding has been upgraded from version 2.19 to 2.20.

  • ExtUtils::CBuilder has been upgraded from version 0.280225 to 0.280228.

  • feature has been upgraded from version 1.48 to 1.49.

  • File::Glob has been upgraded from version 1.28 to 1.29.

  • File::Spec and Cwd have been upgraded from version 3.67 to 3.68.

  • List::Util has been upgraded from version 1.46_02 to 1.48.

  • Math::BigRat has been upgraded from version 0.2611 to 0.2613.

  • Module::CoreList has been upgraded from version 5.20170621 to 5.20170720.

  • Opcode has been upgraded from version 1.39 to 1.40.

  • PerlIO::scalar has been upgraded from version 0.27 to 0.29.

  • POSIX has been upgraded from version 1.76 to 1.77.

  • re has been upgraded from version 0.34 to 0.35.

  • Scalar::Util has been upgraded from version 1.46_02 to 1.48.

  • Time::HiRes has been upgraded from version 1.9741 to 1.9743.

  • Time::Piece has been upgraded from version 1.31 to 1.3201.

Selected Bug Fixes

  • List assignment (aassign) could in some rare cases allocate an entry on the mortal stack and leave the entry uninitialized. [perl #131570]

  • Attempting to apply an attribute to an our variable where a function of that name already exists could result in a NULL pointer being supplied where an SV was expected, crashing perl. [perl #131597]

  • split ' ' now correctly handles the argument being split when in the scope of the unicode_strings feature. Previously, when a string using the single-byte internal representation contained characters that are whitespace by Unicode rules but not by ASCII rules, it treated those characters as part of fields rather than as field separators. [perl #130907]

  • Several built-in functions previously had bugs that could cause them to write to the internal stack without allocating room for the item being written. In rare situations, this could have led to a crash. These bugs have now been fixed, and if any similar bugs are introduced in future, they will be detected automatically in debugging builds.

  • Using a symbolic ref with postderef syntax as the key in a hash lookup was yielding an assertion failure on debugging builds. [perl #131627]

  • Array and hash variables whose names begin with a caret now admit indexing inside their curlies when interpolated into strings, as in "${^CAPTURE[0]}" to index @{^CAPTURE}. [perl #131664]


Perl 5.27.2 represents approximately 4 weeks of development since Perl 5.27.1 and contains approximately 26,000 lines of changes across 290 files from 18 authors.

Excluding auto-generated files, documentation and release tools, there were approximately 9,700 lines of changes to 150 .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 5.27.2:

Aaron Crane, Alberto Simões, Chris 'BinGOs' Williams, Dagfinn Ilmari Mannsåker, David Mitchell, E. Choroba, Eric Herman, Father Chrysostomos, James E Keenan, Karl Williamson, Lukas Mai, Ricardo Signes, Sawyer X, Steve Hay, Tony Cook, Vitali Peil, Yves Orton, Zefram.

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.

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

If you find what you think is a bug, you might check the perl bug database at https://rt.perl.org/ . 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 see "SECURITY VULNERABILITY CONTACT INFORMATION" in perlsec for details of how to report the issue.

Give Thanks

If you wish to thank the Perl 5 Porters for the work we had done in Perl 5, you can do so by running the perlthanks program:


This will send an email to the Perl 5 Porters list with your show of thanks.


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.