Feature or enhancement

Proposal:

Cross-builds depend on a fair bit of sysconfig internals, it would be good have a test in the CI to ensure they work.

This would have prevented #127178 (comment).

I don't think there's a need to run the full test suite, we should be fine running just the sysconfig, site, and test_embed tests. It would also make sense to run the tests in the build directory, and after installation.

The test should consist of:

• Building a host Python, specifying a custom prefix (eg. workdir/host-python)
• Installing the host Python
• Configuring a new build using --with-build-python=workdir/host-python/bin/python, and also using a custom prefix (eg. workdir/cross-python)
• Running the tests in the build directory (./python -m test test_sysconfig test_site test_embed)
• Installing the cross-build
• Running the tests again, but with the installed Python (workdir/cross-python/bin/python -m test test_sysconfig test_site test_embed)

I think we should be fine with Linux-only, but Windows would also be welcome. Additionally, possibly, we could also use a different architecture in the cross-build, like jit.yml does for "Emulated Linux".

Has this already been discussed elsewhere?

No response given

Links to previous discussion of this feature:

No response

Linked PRs

• gh-127432: Add CI test for cross-builds #127447
• gh-127432: Add CI job to cross build Python #128380
• GH-127432: add cross-build-linux as a required CI job #129459