You are viewing the version of this documentation from Perl 5.20.2. View the latest version



perl5122delta - what is new for perl v5.12.2


This document describes differences between the 5.12.1 release and the 5.12.2 release.

If you are upgrading from an earlier major version, such as 5.10.1, first read perl5120delta, which describes differences between 5.10.1 and 5.12.0, as well as perl5121delta, which describes earlier changes in the 5.12 stable release series.

Incompatible Changes

There are no changes intentionally incompatible with 5.12.1. If any exist, they are bugs and reports are welcome.

Core Enhancements

Other than the bug fixes listed below, there should be no user-visible changes to the core language in this release.

Modules and Pragmata

New Modules and Pragmata

This release does not introduce any new modules or pragmata.

Pragmata Changes

In the previous release, no VERSION; statements triggered a bug which could cause feature bundles to be loaded and strict mode to be enabled unintentionally.

Updated Modules


Upgraded from version 1.16 to 1.17.

Carp now detects incomplete caller() overrides and avoids using bogus @DB::args. To provide backtraces, Carp relies on particular behaviour of the caller built-in. Carp now detects if other code has overridden this with an incomplete implementation, and modifies its backtrace accordingly. Previously incomplete overrides would cause incorrect values in backtraces (best case), or obscure fatal errors (worst case)

This fixes certain cases of Bizarre copy of ARRAY caused by modules overriding caller() incorrectly.


A patch to cpanp-run-perl has been backported from CPANPLUS 0.9004. This resolves RT #55964 and RT #57106, both of which related to failures to install distributions that use Module::Install::DSL.


A regression which caused a failure to find CORE::GLOBAL::glob after loading File::Glob to crash has been fixed. Now, it correctly falls back to external globbing via pp_glob.


File::Copy::copy(FILE, DIR) is now documented.


Upgraded from version 3.31 to 3.31_01.

Several portability fixes were made in File::Spec::VMS: a colon is now recognized as a delimiter in native filespecs; caret-escaped delimiters are recognized for better handling of extended filespecs; catpath() returns an empty directory rather than the current directory if the input directory name is empty; abs2rel() properly handles Unix-style input.

Utility Changes

Changes to Existing Documentation

Installation and Configuration Improvements

Configuration improvements

Compilation improvements

Selected Bug Fixes

Platform Specific Notes





Perl 5.12.2 represents approximately three months of development since Perl 5.12.1 and contains approximately 2,000 lines of changes across 100 files from 36 authors.

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 5.12.2:

Abigail, Ævar Arnfjörð Bjarmason, Ben Morrow, brian d foy, Brian Phillips, Chas. Owens, Chris 'BinGOs' Williams, Chris Williams, Craig A. Berry, Curtis Jewell, Dan Dascalescu, David Golden, David Mitchell, Father Chrysostomos, Florian Ragwitz, George Greer, H.Merijn Brand, Jan Dubois, Jesse Vincent, Jim Cromie, Karl Williamson, Lars Dɪᴇᴄᴋᴏᴡ 迪拉斯, Leon Brocard, Maik Hentsche, Matt S Trout, Nicholas Clark, Rafael Garcia-Suarez, Rainer Tammer, Ricardo Signes, Salvador Ortiz Garcia, Sisyphus, Slaven Rezic, Steffen Mueller, Tony Cook, Vincent Pit and Yves Orton.

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 . 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 please send it to 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.


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.