Add C compiler dep when .xs files are found.

[xileF1337]

Description

For many Perl modules, a C compiler dependency is not added to meta.yaml created by conda skeleton cpan even though it is required. This is because C files for Perl modules are commonly stored in files with .xs extension, which are not currently recognized by conda skeleton cpan. This PR adds detection for the .xs extension such that the required dependencies are automatically added. This fixes #4598.

Checklist - did you ...

• Add a file to the news directory (using the template) for the next release's release notes?
• Add / update necessary tests?
• Add / update outdated documentation?

[xileF1337]

The pre-commit CI job fails due to tests/test_index.py:206:5: E303 too many blank lines (2), but I have not touched this file. So it is not my job to fix it I guess?

[mbargull]

Thanks for improving this!
There aren't many people knowledgeable about these things in our community, so I very much appreciate your input. Also, thanks for the detailed description in gh-4598 -- very helpful to properly review this without needing to learn the ins and outs of Perl packaging :).
Sorry it took so long to get this reviewed. Not many/any of us are involved with Perl (packaging), plus conda-skeleton will likely be deprecated (see gh-4640) which is why it's not high on anyone's (long) ToDo list, I suppose...

That said, the changes are fine and contained to skeleton.cpan, so I hope this is okay to be merged soon!

[xileF1337]

Thanks for improving this! There aren't many people knowledgeable about these things in our community, so I very much appreciate your input. Also, thanks for the detailed description in gh-4598 -- very helpful to properly review this without needing to learn the ins and outs of Perl packaging :). Sorry it took so long to get this reviewed. Not many/any of us are involved with Perl (packaging), plus conda-skeleton will likely be deprecated (see gh-4640) which is why it's not high on anyone's (long) ToDo list, I suppose...

I'm glad if I could help. I understand that Perl support does not have a super high priority for people who don't use it themselves. Still, it would be a lot more motivating for further contributions to get feedback a little bit faster, especially for one-line fixes to severe bugs. I still appreciate that you are taking care of this now. Concerning the deprecation of conda skeleton: I suppose this will still take a while since there is currently not even R/CRAN support implemented in the successor grayskull, not to speak of Perl/CPAN. I hope that conda skeleton will be supported until this is available ...

That said, the changes are fine and contained to skeleton.cpan, so I hope this is okay to be merged soon!

That would be awesome, thank you!

[xileF1337]

@mbargull, happy new year! Are we ready to merge here? Thanks for your support!

[xileF1337]

Hey @mbargull, is there anything left to do here except for pushing the merge button? Thanks for your time!

[xileF1337]

@mbargull It would be awesome if you could just push that button! Thank you so much!

[kenodegard]

@xileF1337 Again, thanks for working on this. As @mbargull alluded to Perl and conda skeleton has unfortunately not been a strong suite for the development team so it fell through the cracks. If you want to learn more about what we are doing to try to rectify these issues check out #4697.

@mbargull Thanks as always.