Please make the MCE dependency optional

[karenetheridge]

Would it be possible to add the MCE prereq to 'recommends' instead of 'requires', and only make use of it when installed? This is to prevent dependency bloat on systems where it's not wanted.

[thaljef]

As I recall, the toolchain does not install recommended modules by default. I would prefer to have an opt-out instead of opt-in. So MCE would be required, unless you explicitly say you don't want it.

Would that be acceptable?

[karenetheridge]

So MCE would be required, unless you explicitly say you don't want it.

I guess that depends on how you propose to implement that.

[karenetheridge]

PS CPAN.pm does default to installing recommendations.

[thaljef]

I guess that depends on how you propose to implement that.

Probably as a Build.PL command line option, with an environment variable hook. Other suggestions?

CPAN.pm does default to installing recommendations.

I didn't know that. Thanks for educating me. But cpanm still does not.

[karenetheridge]

This is the canonical way to handle optional features with prompts:

in Makefile.PL:

my %WriteMakefileArgs = (
   ...
);

WriteMakefileArgs{PREREQ_PM}{'MCE'} = '0'
  if $ENV{PERL_MM_USE_DEFAULT} or prompt("install MCE (to allow parallelized tests)? [Y/n]", 'Y') =~ /^y/i;

WriteMakefileArgs{META_MERGE}{optional_features}{'parallel_testing'} = {
  description => 'parallel tests',
  prereqs => { runtime => { requires => { 'MCE' => '0' } } },
  x_default => 1,
};

WriteMakefile(%WriteMakefileArgs);

This will add the extra prereq unless the user specifically said 'no' to the
prompt (and in non-interactive installs, it defaults to 'yes').

I don't know how to do meta merging in Module::Build, but I wouldn't ever
recommend using MB anyway unless you really needed to (e.g. in an Alien dist).

[thaljef]

This is the canonical way to handle optional features with prompts:

Thanks for that.

MB was a decision we made long ago, when MB was more fashionable. I could probably switch Test::Perl::Critic to EU::MM in the near future, but Perl::Critic itself will be harder to migrate.

[karenetheridge]

we can help on #toolchain :)

[marioroy]

++ for adding the MCE prereq to 'recommends' instead of 'requires'

[karenetheridge]

Hi all. I never knew that moving older MCE releases to backPan causes this. That is not safe to do. Going forward, will not move MCE releases to backPan. :(

uh, what? moving things to backpan is recommended, to free up space on mirrors, and should not be causing tooling issues.

…

On Tue, Mar 7, 2017 at 3:13 AM, Mario Roy ***@***.***> wrote: Hi all. I never knew that moving older MCE releases to backPan causes this. That is not safe to do. Going forward, will not move MCE releases to backPan. :( — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub <#1 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AASfyy6GPE0yZZx1lpOWCxcwzwV2VF0Yks5rjTv1gaJpZM4DbIqw> .

[marioroy]

Thank you. I had mistakenly mis-diagnosed an email reply on issue #707.

[petdance]

I'm certainly in favor of moving back to vanilla Makemaker. If I do that, I'll make MCE optional.

[iynehz]

++