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 => 'passthrough' );
 ...

Because ExtUtils::MakeMaker has been the standard way to distribute modules for a long time, many tools (CPAN.pm, 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.

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

small

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.

passthrough

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

traditional

A Makefile.PL will be created in the traditional style, i.e. it will use CWExtUtils::MakeMaker and won't rely on CWModule::Build at all. In order to create the Makefile.PL, we'll include the CWrequires and CWbuild_requires dependencies as the CWPREREQ_PM parameter. You don't want to use this style if during the CWperl 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.

run_build_pl( args => \@ARGV )

This method runs the Build.PL script, passing it any arguments the user may have supplied to the CWperl Makefile.PL command. Because ExtUtils::MakeMaker and Module::Build accept different arguments, this method also performs some translation between the two. CWrun_build_pl() accepts the following named parameters:

args

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

script

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

write_makefile()

This method writes a 'dummy' Makefile that will pass all commands through to the corresponding Module::Build actions. CWwrite_makefile() accepts the following named parameters:

makefile

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

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/CWExtUtils::MakeMaker way of doing things.

2.

Include a Build.PL script and a traditional Makefile.PL, created either manually or with CWcreate_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. If you go this route, make sure you explicitly set CWPL_FILES in the call to CWWriteMakefile() (probably to an empty hash reference), or else MakeMaker will mistakenly run the Build.PL and you'll get an error message about Too early to run Build script or something. 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, ken@mathforum.org

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