rework module_generator to avoid keeping state w.r.t. fake modules

[boegel]

fix (+ enhanced unit test) for #1329, reported by @DirkdeDraak and @rjeschmi

[boegel]

@rjeschmi: up for reviewing this? maybe @pforai can take a look too, since he has played around in module_generator.py quite a bit in the past

[hpcugentbot]

Refer to this link for build results (access rights to CI server needed):
https://jenkins1.ugent.be/job/easybuild-framework-pr-builder/1964/
EasyBuild framework unit test suite PASSed (see https://jenkins1.ugent.be/job/easybuild-framework-pr-builder/1964/console for more details).

This pull request is now ready for review/testing.

Please try and find someone who can tackle this; contact @boegel if you're not sure what to do.

[rjeschmi]

Yeah, this is generally what I thought needed to be done (but didn't really know how to do). Most of the state information wasn't helpful and was ripe for side-effects.

I'll try testing it, but otherwise looks good.

[rjeschmi]

tested it and it seems to work fine with packaging.

[JensTimmerman]

ok

[boegel]

Thanks for the reviewing/testing @rjeschmi and @JensTimmerman!