Dist::Zilla::Plugin::Breaks - Add metadata about potential breakages caused by your distribution


version 0.004


In your dist.ini:

    Foo::Bar = <= 1.0       ; anything at this version or below is out of date
    Foo::Baz = == 2.35      ; just this one exact version is problematic


This plugin adds distribution metadata regarding other modules and version that are not compatible with your distribution's release. It is not quite the same as the conflicts field in prerequisite metadata (see "Relationships" in CPAN::Meta::Spec), but rather indicates what modules will likely not work once your distribution is installed.

This is a not-uncommon problem when modifying a module's API - there are other existing modules out on the CPAN (or a darkPAN) which use the old API, and will need to be updated when the new API is removed. These modules are not prerequisites -- our distribution does not use those modules, but rather those modules use us. So, it's not valid to list those modules in our prerequisites -- besides, it would likely (almost certainly) be a circular dependency!

The data is added to metadata in the form of the x_breaks field, as set out by the Lancaster consensus. The exact syntax and use may continue to change until it is accepted as an official part of the meta specification.

Version ranges can and normally should be specified; see "Version Ranges" in CPAN::Meta::Spec. They are interpreted as for conflicts -- version(s) specified indicate the bad versions of modules, not version(s) that must be present for normal operation. That is, packages should be specified with the version(s) that will not work when your distribution is installed; for example, if all version of Foo::Bar up to and including 1.2 will break, but a release of 1.3 will work, then specify the breakage as:

    Foo::Bar = <= 1.2

or more accurately:

    Foo::Bar = < 1.3

A bare version with no operator is interpreted as >= -- all versions at or above the one specified are considered bad -- which is generally not what you want to say!

The [Test::CheckBreaks] plugin can generate a test for your distribution that will check this field and provide diagnostic information to the user should any problems be identified.

Additionally, the [Conflicts] plugin can generate x_breaks data, as well as a (non-standard) mechanism for checking for conflicts from within Makefile.PL/Build.PL.



Bugs may be submitted through the RT bug tracker (or

There is also a mailing list available for users of this distribution, at

There is also an irc channel available for users of this distribution, at #distzilla on

I am also usually active on irc, as 'ether' at


Karen Etheridge <>


This software is copyright (c) 2014 by Karen Etheridge.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.