BLD: wasm build

[andyfaff]

No description provided.

[andyfaff]

I seem to be able to start the wheel build, but the build fails with:

../meson.build:1:0: ERROR: Emscripten compiler can only be used for cross compilation.

The build is done with the following command:

python -m cibuildwheel numpy-src --config-file cibuildwheel.toml --output-dir ./dist

Are there extra options I need to add?
The build works with the cibuildwheel action in the main repo.

@rgommers

EDIT: extra stuff is required from pyproject.toml

[andyfaff]

No idea why it works on numpy/numpy with cp313, but not here. cp312 works ok.

[andyfaff]

@rgommers ping

[andyfaff]

@rgommers, I now know what the issue is with building the pyodide wheels, see the cibuildwheel issue I submitted. We can get around the issue temporarily by using the pypa/cibuildwheel action, but that would require whitelisting it. I'm trying to address numpy/numpy#29462 (comment) with this PR.

[agriyakhetarpal]

Hi! Thank you for filing the upstream issue in cibuildwheel – I will investigate it soon. In the meantime, I'd say it would be a good idea to allowlist the pypa/cibuildwheel action from a security perspective: all dependencies that affect the build process are pinned using constraints, and it is well-supported and maintained. Additionally, the cibuildwheel test suite runs its action with the CIBW_PLATFORM set to pyodide, so it is thoroughly tested as well. While I believe that using actions/setup-python and python -m cibuildwheel is a less popular approach for users, it is possible that there might be subtle bugs to be uncovered, and that we could do something to avert them.

cc: @hoodmane @ryanking13 for awareness

[ryanking13]

Thanks for the ping. I think the cross file should be passed to meson to make it aware that it is cross compilation, but looking at the build log it doesn't seems to be passed for some reason.

[andyfaff]

I think it is being passed, otherwise the tests would fail.

[ryanking13]

Oh, yes, I think it is passed now. I was looking at the original error message about the cross compilation, and thought that it was not resolved yet.

../meson.build:1:0: ERROR: Emscripten compiler can only be used for cross compilation.