Specify CPU type as a virtual package

[m3vaz]

Checklist

• I added a descriptive title
• I searched for other feature requests and couldn't find a duplicate (including also the type-feature tag)
• I confirmed that it's not related to another project (see the above section)

What is the idea?

The conda compilers can target and tune for specific cpu architectures, however this information isn't stored in the package description and can't be selected for at install time.

Compiling and tuning for specific architectures is a use case for developers that want to provide performant packages for the users that want them. It would also stop incompatible packages from being used on machines that can't run the binaries.

Why is this needed

Compilers can target specific architectures, but there's no way to communicate that information in the package description or select for it. It effectively means that for linux-64 packages, developers need to be targeting -march=x86_64 in order to insure that users always have compatible packages, and it also means that targeted performance tuning for specific CPU's is not available.

What should happen?

A virtual package(s) should be available describing the underlying host cpu capabilities, similar to the __cuda virtual package

Additional Context

This is related to #11457 which results in incompatible packages being compiled.

[leofang]

Possibly related: #9818

[leofang]

Parallel discussion on conda-forge: conda-forge/conda-forge.github.io#1261

[leofang]

(cc: @jakirkham for vis)

[jezdez]

This is a good idea and will go splendidly with what we're working on for the next conda release in #11854.

[github-actions]

Hi there, thank you for your contribution!

This issue has been automatically marked as stale because it has not had recent activity. It will be closed automatically if no further activity occurs.

If you would like this issue to remain open please:

1. Verify that you can still reproduce the issue at hand
2. Comment that the issue is still reproducible and include:
   - What OS and version you reproduced the issue on
   - What steps you followed to reproduce the issue

NOTE: If this issue was closed prematurely, please leave a comment.

Thanks!

[jakirkham]

Let's keep this open