Module::Build::Compat - Compatibility with ExtUtils::MakeMaker


  # In a Build.PL :
  use Module::Build;
  my $build = Module::Build->new
    ( module_name => 'Foo::Bar',
      license     => 'perl',
      create_makefile_pl => 'traditional' );


Because ExtUtils::MakeMaker has been the standard way to distribute modules for a long time, many tools (, or your system administrator) may expect to find a working Makefile.PL in every distribution they download from CPAN. If you want to throw them a bone, you can use Module::Build::Compat to automatically generate a Makefile.PL for you, in one of several different styles.

Module::Build::Compat also provides some code that helps out the Makefile.PL at runtime.


Note that Module::Build::Compat more often causes installation issues than solves them, and each of the three Makefile.PL generation styles has unique compatibility or functionality issues that are unlikely to be fixed. Thus, the use of this module and create_makefile_pl is discouraged.


create_makefile_pl($style, $build)

Creates a Makefile.PL in the current directory in one of several styles, based on the supplied Module::Build object $build. This is typically controlled by passing the desired style as the create_makefile_pl parameter to Module::Build's new() method; the Makefile.PL will then be automatically created during the distdir action.

The currently supported styles are:


A Makefile.PL will be created in the "traditional" style, i.e. it will use ExtUtils::MakeMaker and won't rely on Module::Build at all. In order to create the Makefile.PL, we'll include the requires and build_requires dependencies as the PREREQ_PM parameter.

You don't want to use this style if during the perl Build.PL stage you ask the user questions, or do some auto-sensing about the user's environment, or if you subclass Module::Build to do some customization, because the vanilla Makefile.PL won't do any of that. Many standard Module::Build features such as test_requires are also not supported.


A small Makefile.PL will be created that passes all functionality through to the Build.PL script in the same directory. The user must already have Module::Build installed in order to use this, or else they'll get a module-not-found error.

This style attempts (with varying success) to translate the Makefile.PL protocol to Build.PL, and is unnecessary on any modern toolchain that recognizes configure_requires metadata described below, as Build.PL will be run by default in this case. See for an example of the issues it may cause.

passthrough (DEPRECATED)

This is just like the small option above, but if Module::Build is not already installed on the user's system, the script will offer to use to download it and install it before continuing with the build.

This option has been deprecated and may be removed in a future version of Module::Build. Modern and CPANPLUS will recognize the configure_requires metadata property and install Module::Build before running Build.PL if Module::Build is listed and Module::Build now adds itself to configure_requires by default.

Perl 5.10.1 includes configure_requires support. In the future, when configure_requires support is deemed sufficiently widespread, the passthrough style will be removed.

run_build_pl(args => \@ARGV)

This method runs the Build.PL script, passing it any arguments the user may have supplied to the perl Makefile.PL command. Because ExtUtils::MakeMaker and Module::Build accept different arguments, this method also performs some translation between the two.

run_build_pl() accepts the following named parameters:


The args parameter specifies the parameters that would usually appear on the command line of the perl Makefile.PL command - typically you'll just pass a reference to @ARGV.


This is the filename of the script to run - it defaults to Build.PL.


This method writes a 'dummy' Makefile that will pass all commands through to the corresponding Module::Build actions.

write_makefile() accepts the following named parameters:


The name of the file to write - defaults to the string Makefile.


So, some common scenarios are:

  1. Just include a Build.PL script (without a Makefile.PL script), and give installation directions in a README or INSTALL document explaining how to install the module. In particular, explain that the user must install Module::Build before installing your module.

    Note that if you do this, you may make things easier for yourself, but harder for people with older versions of CPAN or CPANPLUS on their system, because those tools generally only understand the Makefile.PL/ExtUtils::MakeMaker way of doing things.

  2. Include a Build.PL script and a "traditional" Makefile.PL, created either manually or with create_makefile_pl(). Users won't ever have to install Module::Build if they use the Makefile.PL, but they won't get to take advantage of Module::Build's extra features either.

    For good measure, of course, test both the Makefile.PL and the Build.PL before shipping.

  3. Include a Build.PL script and a "pass-through" Makefile.PL built using Module::Build::Compat. This will mean that people can continue to use the "old" installation commands, and they may never notice that it's actually doing something else behind the scenes. It will also mean that your installation process is compatible with older versions of tools like CPAN and CPANPLUS.


Ken Williams <>


Copyright (c) 2001-2006 Ken Williams. All rights reserved.

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


Module::Build(3), ExtUtils::MakeMaker(3)