ENH add migration for gcc 9.3.0

[beckermr]

Checklist

• Used a personal fork of the feedstock to propose changes
• Bumped the build number (if the version is unchanged)
• Reset the build number to 0 (if the version changed)
• Re-rendered with the latest conda-smithy (Use the phrase @conda-forge-admin, please rerender in a comment in this PR for automated rerendering)
• Ensured the license file is being packaged.

[conda-forge-linter]

Hi! This is the friendly automated conda-forge-linting service.

I just wanted to let you know that I linted all conda-recipes in your PR (recipe) and found it was in an excellent condition.

[beckermr]

This is waiting on the rebuild of gfortran on osx so that the hashes in the compilers are unique.

[isuruf]

Aren't we going to build both?

[isuruf]

Can you also clean up the versions in conda_build_config.yaml?

[beckermr]

Build both versions of gfortran?

[beckermr]

Aren't we going to build both?

I still don't follow this question @isuruf.

I think I got the rest of the changes.

[isuruf]

I was under the impression that this will take a long time as well and that we should build both versions (7 and 9) to not interfere other migrations.

[beckermr]

Ahhhh. I can put back the version 7 on osx and linux. We don't need it on aarch or ppc since the SONAME is the same.

[isuruf]

aarch64 used 7.*. For ppc64le, we still need to rebuild for the new run_exports to work (unless we do a repodata patch).

[beckermr]

@conda-forge/core as currently set up, this migration will remove any compiler pins related to armv7l builds. Do we need those platforms at all?

[beckermr]

aarch64 used 7.*. For ppc64le, we still need to rebuild for the new run_exports to work (unless we do a repodata patch).

Right. I think I got the old 7 platforms correct. I can add 8 for ppc64le

[jjhelmus]

@conda-forge/core as currently set up, this migration will remove any compiler pins related to armv7l builds. Do we need those platforms at all?

The armv7l platform can be removed, it is not being built. If someone wants to add this platform to conda-forge in the future they can re-add the correct pins.

[beckermr]

great @jjhelmus! I think this is ready to merge then!

[beckermr]

Any other comments here @conda-forge/core?

[beckermr]

announcement here: conda-forge/conda-forge.github.io#1166