It's a little complicated; basically, in some ways, M::B is a step backwards, not a step forwards.
Under EU::MM, to determine dependencies, you run Makefile.PL, which is allowed to tailor a list of dependencies specific to that particular installation, then read the dependencies from the "# PREREQ_PM" line in the generated Makefile.
Under M::B, AIUI, dependencies are hardcoded in META.yml (though it does have the nice distinction between requires: and build_requires:).
ActiveState seems to make a real attempt to validate the dependencies by running Makefile.PL in a clean environment,
adding any resulting dependencies, then doing the make.
But Makefile.PL's built with Module::Build::Compat's small or passthrough options require Module::Build to be installed or installable to work at a point where in the EU::MM universe, dependency information isn't yet available. You can see a passthrough Makefile.PL in action here.
Module::Build::Compat's traditional option will work, but that won't do everything Build.PL can, so I'm not sure I see the point in not just staying with EU::MM (especially for existing modules).
An additional note: even if META.yml were checked before running Makefile.PL, in the examples I've seen, Module::Build isn't listed as a dependency there even though it is required for the build. | [reply] |
Under M::B, AIUI, dependencies are hardcoded in META.yml
This is incorrect.
M::B describes dependencies in its Build.PL just like EU::MM describes its dependences in Makefile.PL. The META.yml is generated from this description (as, indeed, it is with the latest EU::MM).
An additional note: even if META.yml were checked before running Makefile.PL, in the examples I've seen, Module::Build isn't listed as a dependency there even though it is required for the build.
Just as EU::MM isn't included in the META.yml files that EU::MM generates.
| [reply] |
With the small difference that EU::MM is in the Perl core and thus can be expected to be available, whereas Module::Build isn't. There remains the issue of version incompatibilities between different EU::MM versions of course, but seemingly that issue is not as apparent.
| [reply] |
Thanks for correcting me. I saw the build action didn't regenerate META.yml, so assumed incorrectly that a way for
Build.PL to indicate requirements to an external tool.
I see now that the distmeta action does this (the "dist"
prefix had made me think it was something that should only
be done as part of preparing a distribution), or you can
do what CPANPLUS does after running the build action:
my $build = Module::Build->resume(
properties => {
config_dir => File::Spec->catdir($args->{'dir'}, "_build"
+),
build_script => 'Build',
}
);
my $failures = $build->prereq_failures;
| [reply]
[d/l] |
| [reply] |