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PERL52512DELTA(1) Perl Programmers Reference Guide PERL52512DELTA(1)


perl52512delta - what is new for perl v5.25.12


This document describes differences between the 5.25.11 release and the 5.25.12 release.

If you are upgrading from an earlier release such as 5.25.10, first read perl52511delta, which describes differences between 5.25.10 and 5.25.11.

Modules and Pragmata

Updated Modules and Pragmata

  • base has been upgraded from version 2.24 to 2.25.
  • CPAN has been upgraded from version 2.17 to 2.18.
  • DynaLoader has been upgraded from version 1.41 to 1.42.
  • Module::CoreList has been upgraded from version 5.20170320 to 5.20170420.
  • Safe has been upgraded from version 2.39 to 2.40.
  • threads::shared has been upgraded from version 1.55 to 1.56.
  • XSLoader has been upgraded from version 0.26 to 0.27.


New Diagnostics

New Errors
Since "." is now removed from @INC by default, "do" will now trigger a warning recommending to fix the "do" statement:

do "%s" failed, '.' is no longer in @INC

Changes to Existing Diagnostics

  • When a "require" fails, we now do not provide @INC when the "require" is for a file instead of a module.
  • When @INC is not scanned for a "require" call, we no longer display @INC to avoid confusion.


Perl 5.25.12 represents approximately 4 weeks of development since Perl 5.25.11 and contains approximately 1,700 lines of changes across 150 files from 8 authors.

Excluding auto-generated files, documentation and release tools, there were approximately 700 lines of changes to 73 .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 5.25.12:

Chris 'BinGOs' Williams, Dagfinn Ilmari Mannsåker, David Mitchell, James E Keenan, Jarkko Hietaniemi, Karl Williamson, Pali, Sawyer X.

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 <> . There may also be information at <> , 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 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.


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.

2017-05-20 perl v5.26.0