++ed by:

179 PAUSE users
175 non-PAUSE users.

Chris Williams
and 1 contributors


perl5273delta - what is new for perl v5.27.3


This document describes differences between the 5.27.2 release and the 5.27.3 release.

If you are upgrading from an earlier release such as 5.27.1, first read perl5272delta, which describes differences between 5.27.1 and 5.27.2.


Module removals

The following modules will be removed from the core distribution in a future release, and will at that time need to be installed from CPAN. Distributions on CPAN which require these modules will need to list them as prerequisites.

The core versions of these modules will now issue "deprecated"-category warnings to alert you to this fact. To silence these deprecation warnings, install the modules in question from CPAN.

Note that these are (with rare exceptions) fine modules that you are encouraged to continue to use. Their disinclusion from core primarily hinges on their necessity to bootstrapping a fully functional, CPAN-capable Perl installation, not usually on concerns over their design.


Performance Enhancements

  • SvTRUE() is now more efficient.

  • keys() in void and scalar contexts is now more efficient.

  • Various integer-returning ops are now more efficient in scalar/boolean context.

  • if (index(...) != -1) { ... } is now more efficient.

  • for() loops and similar constructs are now more efficient in most cases.

Modules and Pragmata

Updated Modules and Pragmata

  • B has been upgraded from version 1.68 to 1.69.

  • B::Concise has been upgraded from version 1.000 to 1.001.

  • B::Debug has been upgraded from version 1.24 to 1.25. NOTE: B::Debug is deprecated and may be removed from a future version of Perl.

  • B::Deparse has been upgraded from version 1.41 to 1.42.

  • base has been upgraded from version 2.25 to 2.26.

  • Data::Dumper has been upgraded from version 2.167 to 2.167_02.

  • Devel::Peek has been upgraded from version 1.26 to 1.27.

  • ExtUtils::Constant has been upgraded from version 0.23 to 0.24.

  • ExtUtils::ParseXS has been upgraded from version 3.34 to 3.35.

  • ExtUtils::Typemaps has been upgraded from version 3.34 to 3.35.

  • Filter::Simple has been upgraded from version 0.93 to 0.94.

  • Module::CoreList has been upgraded from version 5.20170720 to 5.20170821.

  • SelfLoader has been upgraded from version 1.23 to 1.24.

  • Storable has been upgraded from version 2.63 to 2.64.

  • threads has been upgraded from version 2.16 to 2.17.

  • utf8 has been upgraded from version 1.19 to 1.20.

Configuration and Compilation

  • On GCC, -Werror=pointer-arith is now enabled by default, disallowing arithmetic on void and function pointers.

Selected Bug Fixes

  • Fixed a duplicate symbol failure with -flto -mieee-fp builds. pp.c defined _LIB_VERSION which -lieee already defines. [perl #131786]

  • The tokenizer no longer consumes the exponent part of a floating point number if it's incomplete. [perl #131725]

  • On non-threaded builds, for m/$null/ where $null is an empty string is no longer treated as if the /o flag was present when the previous matching match operator included the /o flag. The rewriting used to implement this behavior could confuse the interpreter. This matches the behaviour of threaded builds. [perl #124368]


Perl 5.27.3 represents approximately 5 weeks of development since Perl 5.27.2 and contains approximately 5,600 lines of changes across 150 files from 19 authors.

Excluding auto-generated files, documentation and release tools, there were approximately 4,000 lines of changes to 84 .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 5.27.3:

Aaron Crane, Aristotle Pagaltzis, Chris 'BinGOs' Williams, Craig A. Berry, Dagfinn Ilmari Mannsåker, Daniel Dragan, David Mitchell, Father Chrysostomos, James E Keenan, Karl Williamson, Ken Brown, Lukas Mai, Matthew Horsfall, Nicholas Clark, Robin Barker, Steffen Müller, Steve Hay, Tony Cook, 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.