Dist::Zilla::Plugin::ModuleBuildTiny::Fallback - Generate a Build.PL that uses Module::Build::Tiny and Module::Build


version 0.027


In your dist.ini:



This is a Dist::Zilla plugin that provides a Build.PL in your distribution that attempts to use Module::Build::Tiny when available, falling back to Module::Build when it is missing.

This is useful when your distribution is installing on an older perl (before approximately 5.10.1) with a toolchain that has not been updated, where configure_requires metadata is not understood and respected -- or where Build.PL is being run manually without the user having read and understood the contents of META.yml or META.json.

When the Module::Build fallback code is run, an added preamble is printed:


    If you're seeing this warning, your toolchain is really, really old* and
    you'll almost certainly have problems installing CPAN modules from this
    century. But never fear, dear user, for we have the technology to fix this!

    If you're using to install things, then you can upgrade it using:

    cpan CPAN

    If you're using CPANPLUS to install things, then you can upgrade it using:

    cpanp CPANPLUS

    If you're using cpanminus, you shouldn't be seeing this message in the first
    place, so please file an issue on github.

    This public service announcement was brought to you by the Perl Toolchain
    Gang, the #toolchain IRC channel, and the number 42.


    * Alternatively, you are running this file manually, in which case you need to
    learn to first fulfill all configure requires prerequisites listed in META.yml
    or META.json -- or use a cpan client to install this distribution.

    You can also silence this warning for future installations by setting the
    PERL_MB_FALLBACK_SILENCE_WARNING environment variable, but please don't do
    that until you fix your toolchain as described above.

This plugin internally calls both the [ModuleBuildTiny] and [ModuleBuild] plugins to fetch their normal Build.PL file contents, combining them together into the final Build.PL for the distribution.

You are warned if anything else added content into Build.PL (e.g. some additional build-time dependency checks), as that code will not run in the fallback case. It is up to you to decide whether it is still a good idea to use this plugin in this situation.



Optional. Specifies the minimum version of Module::Build needed for proper fallback execution. Defaults to 0.28.


Optional. Passed to [ModuleBuildTiny] as version: the minimum version of Module::Build::Tiny to depend on (in configure_requires as well as a use assertion in Build.PL).


Peter Rabbitson (ribasushi), for inspiration, and Matt Trout (mst), for not stopping me.



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 and


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.