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[ this is a template for a new perldelta file. Any text flagged as XXX needs to be processed before release. ]

perldelta - what is new for perl v5.41.2


This document describes differences between the 5.41.1 release and the 5.41.2 release.

If you are upgrading from an earlier release such as 5.41.0, first read perl5411delta, which describes differences between 5.41.0 and 5.41.1.


XXX Any important notices here

Core Enhancements

XXX New core language features go here. Summarize user-visible core language enhancements. Particularly prominent performance optimisations could go here, but most should go in the "Performance Enhancements" section.

[ List each enhancement as a =head2 entry ]

New pragma source::encoding

This allows you to declare that the portion of a program for the remainder of the lexical scope of this pragma is encoded either entirely in ASCII (for use source::encoding 'ascii') or if UTF-8 is allowed as well (for use source::encoding 'utf8'). No other encodings are accepted. The second form is entirely equivalent to use utf8, and may be used interchangeably with that.

The purpose of this pragma is to catch cases early where you forgot to specify use utf8.

use source::encoding 'ascii' is automatically enabled within the lexical scope of a use v5.41.0 or higher.

no source::encoding turns off all this checking for the remainder of its lexical scope. The meaning of non-ASCII characters is then undefined.


XXX Any security-related notices go here. In particular, any security vulnerabilities closed should be noted here rather than in the "Selected Bug Fixes" section.

[ List each security issue as a =head2 entry ]

Incompatible Changes

XXX For a release on a stable branch, this section aspires to be:

There are no changes intentionally incompatible with 5.XXX.XXX
If any exist, they are bugs, and we request that you submit a
report.  See L</Reporting Bugs> below.

[ List each incompatible change as a =head2 entry ]


XXX Any deprecated features, syntax, modules etc. should be listed here.

Module removals

XXX Remove this section if not applicable.

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.


XXX Note that deprecated modules should be listed here even if they are listed as an updated module in the "Modules and Pragmata" section.

[ List each other deprecation as a =head2 entry ]

Performance Enhancements

XXX Changes which enhance performance without changing behaviour go here. There may well be none in a stable release.

[ List each enhancement as an =item entry ]

Modules and Pragmata

XXX All changes to installed files in cpan/, dist/, ext/ and lib/ go here. If Module::CoreList is updated, generate an initial draft of the following sections using Porting/ A paragraph summary for important changes should then be added by hand. In an ideal world, dual-life modules would have a Changes file that could be cribbed.

The list of new and updated modules is modified automatically as part of preparing a Perl release, so the only reason to manually add entries here is if you're summarising the important changes in the module update. (Also, if the manually-added details don't match the automatically-generated ones, the release manager will have to investigate the situation carefully.)

[ Within each section, list entries as an =item entry ]

New Modules and Pragmata

Updated Modules and Pragmata

Removed Modules and Pragmata


XXX Changes to files in pod/ go here. Consider grouping entries by file and be sure to link to the appropriate page, e.g. perlfunc.

New Documentation

XXX Changes which create new files in pod/ go here.


XXX Description of the purpose of the new file here

Changes to Existing Documentation

We have attempted to update the documentation to reflect the changes listed in this document. If you find any we have missed, open an issue at

XXX Changes which significantly change existing files in pod/ go here. However, any changes to pod/perldiag.pod should go in the "Diagnostics" section.

Additionally, the following selected changes have been made:



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.

XXX New or changed warnings emitted by the core's C code go here. Also include any changes in perldiag that reconcile it to the C code.

New Diagnostics

XXX Newly added diagnostic messages go under here, separated into "New Errors" and "New Warnings"

New Errors

New Warnings

Changes to Existing Diagnostics

XXX Changes (i.e. rewording) of diagnostic messages go here

Utility Changes

XXX Changes to installed programs such as perldoc and xsubpp go here. Most of these are built within the directory utils.

[ List utility changes as a =head2 entry for each utility and =item entries for each change Use XXX with program names to get proper documentation linking. ]


Configuration and Compilation

XXX Changes to Configure, installperl, installman, and analogous tools go here. Any other changes to the Perl build process should be listed here. However, any platform-specific changes should be listed in the "Platform Support" section, instead.

[ List changes as an =item entry ].


XXX Any significant changes to the testing of a freshly built perl should be listed here. Changes which create new files in t/ go here as do any large changes to the testing harness (e.g. when parallel testing was added). Changes to existing files in t/ aren't worth summarizing, although the bugs that they represent may be covered elsewhere.

XXX If there were no significant test changes, say this:

Tests were added and changed to reflect the other additions and changes in this release.

XXX If instead there were significant changes, say this:

Tests were added and changed to reflect the other additions and changes in this release. Furthermore, these significant changes were made:

[ List each test improvement as an =item entry ]

Platform Support

XXX Any changes to platform support should be listed in the sections below.

[ Within the sections, list each platform as an =item entry with specific changes as paragraphs below it. ]

New Platforms

XXX List any platforms that this version of perl compiles on, that previous versions did not. These will either be enabled by new files in the hints/ directories, or new subdirectories and README files at the top level of the source tree.



Discontinued Platforms

XXX List any platforms that this version of perl no longer compiles on.



Platform-Specific Notes

XXX List any changes for specific platforms. This could include configuration and compilation changes or changes in portability/compatibility. However, changes within modules for platforms should generally be listed in the "Modules and Pragmata" section.



Internal Changes

XXX Changes which affect the interface available to XS code go here. Other significant internal changes for future core maintainers should be noted as well.

[ List each change as an =item entry ]

Selected Bug Fixes

XXX Important bug fixes in the core language are summarized here. Bug fixes in files in ext/ and lib/ are best summarized in "Modules and Pragmata".

XXX Include references to GitHub issues and PRs as: [GH #12345] and the release manager will later use a regex to expand these into links.

[ List each fix as an =item entry ]

Known Problems

XXX Descriptions of platform agnostic bugs we know we can't fix go here. Any tests that had to be TODOed for the release would be noted here. Unfixed platform specific bugs also go here.

[ List each fix as an =item entry ]

Errata From Previous Releases


XXX If any significant core contributor or member of the CPAN community has died, add a short obituary here.


XXX Generate this with:

perl Porting/ v5.41.1..HEAD

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 open an issue at Be sure to trim your bug down to a tiny but sufficient test case.

If the bug you are reporting has security implications which make it inappropriate to send to a public issue tracker, 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.