Add librt as runtime dependency

[cdce8p]

librt is needed both at build and runtime. It's already part of mypy-requirements.txt.

[ilevkivskyi]

Oh, forgot about that one, thanks!

[cdce8p]

Another open issue is the WASM build. Seems it broke after #19945 was merged.
https://github.com/mypyc/mypy_mypyc-wheels/actions/runs/18124228422/job/51575645656

Should we disable it in the wheel builder, at least for now?

[github-actions]

According to mypy_primer, this change doesn't affect type check results on a corpus of open source code. ✅

[ilevkivskyi]

Should we disable it in the wheel builder, at least for now?

Hm, let me check what is going on there.

[ilevkivskyi]

OK, not 100% sure, but the problem may be that librt doesn't have a Python version, nor a WASM wheel. It looks like we will need to ask @emmatyping about what to do with those failures.

[JukkaL]

I don't how have much context on WASM, but cibuildwheel supports pyiodide, which seems relevant: https://cibuildwheel.pypa.io/en/stable/options/#platform

[ilevkivskyi]

I guess I can try adding that to the build matrix (but IIUC only Python 3.12 and 3.13 are supported).

[ilevkivskyi]

Btw, I have another question: is sdist something valuable/meaningful for an extension module? Should I also add sdist for librt?

[JukkaL]

Yeah I think sdist is something we should have, as it will allow building the module on a platform for which we don't provide a binary wheel (e.g. FreeBSD, development version of CPython or maybe even PyPy).

[ilevkivskyi]

OK, it looks like we have a problem: cibuildwheel only supports pyodide on Python 3.12 and 3.13 (according to docs), but we only build WASM wheel for mypy on Python 3.10. So we will need to either:

• Manually build a 3.10 WASM wheel for librt
• Only build WASM wheels for mypy on Python 3.12 and/or 3.13

Which way should we go? I would say the second option looks more future-proof.

[ilevkivskyi]

It looks like I can successfully build WASM wheels using cibuildwheels on Python 3.12 and 3.13, see mypyc/librt#6. There are however a huge backlog on macos GHA runners, so it will probably take hours to release new version of librt.

[ilevkivskyi]

Oh god, it looks like cibuildwheels builds wheels not supported by PyPI?

WARNING  Error during upload. Retry with the --verbose option for more details. 
ERROR    HTTPError: 400 Bad Request from https://upload.pypi.org/legacy/        
         Binary wheel 'librt-0.1.1-cp312-cp312-pyodide_2024_0_wasm32.whl' has an
         unsupported platform tag 'pyodide_2024_0_wasm32'.

why can't we have nice things?

[ilevkivskyi]

Also obviously that "official" GH action creates partially broken releases, now there are only half of the artifacts present for 0.1.1 https://pypi.org/project/librt/0.1.1/#files

[ilevkivskyi]

https://pyodide.org/en/0.26.3/development/building-and-testing-packages.html#notes

for now, PyPi does not support emscripten/wasm32 wheels so you will not be able to upload them there.

[ilevkivskyi]

I guess for now I will continue building WASM wheels, but skip them during upload to PyPI.

[ilevkivskyi]

OK, so I repaired the librt 0.1.1 release. I verified that

pip install -U librt --no-binary librt

works, i.e. all the necessary bits are present in the source archive (like headers) to build the extension locally.

[ilevkivskyi]

I tried re-running failed jobs, but it looks like availability of sdist for librt on PyPI didn't help. I am going to disable the WASM build then until @emmatyping has time to fix it.

[ilevkivskyi]

mypyc/mypy_mypyc-wheels#104