Patch noarch python packages to require python 3

[mariusvniekerk]

Should we patch all python noarch package without a python constraint built after some date (say 2020-10-01) to require python 3?

This should avoid issues with having modern noarch packages being installable in py2 whilst not working.

[isuruf]

I think we can do that if there's no python constraint there. We should first add a lint to add a lower bound on python and maybe also a mini migrator to add python >=3.6

[mariusvniekerk]

In favor of all of that

[betteridiot]

What happens here if a package is explicitly written to work on 2.7 and greater? My code was just linted conda-forge/bamnostic-feedstock#36 and the co-maintainer made the python >= 3.6 update. I was wondering if this update now prevents the package from installing on conda environments using 2.7?

[isuruf]

Yes, the new packages cannot be installed in 2.7, but the old packages can be. If you want to avoid the lint, you can add python >=2.7.