manylinux arm + pypy builds too many wheels

[oscarbenjamin]

I just tested out cibuildwheel 3.0.0b1 in flintlib/python-flint#283 to test building wheels for CPython 3.14. It all seems to be working fine except that too many wheels are built in the manylinux arm job which seems to be caused by pypy pulling in a different docker container.

The other jobs all build 7 wheels e.g. this is what I get for manylinux x86-64:

7 wheels produced in 16 minutes:
  python_flint-0.7.1-cp311-cp311-manylinux_2_17_x86_64.manylinux2014_x86_64.whl          11,297 kB
  python_flint-0.7.1-cp312-cp312-manylinux_2_17_x86_64.manylinux2014_x86_64.whl          11,213 kB
  python_flint-0.7.1-cp313-cp313-manylinux_2_17_x86_64.manylinux2014_x86_64.whl          11,205 kB
  python_flint-0.7.1-cp313-cp313t-manylinux_2_17_x86_64.manylinux2014_x86_64.whl         11,260 kB
  python_flint-0.7.1-cp314-cp314-manylinux_2_17_x86_64.manylinux2014_x86_64.whl          11,205 kB
  python_flint-0.7.1-cp314-cp314t-manylinux_2_17_x86_64.manylinux2014_x86_64.whl         11,260 kB
  python_flint-0.7.1-pp311-pypy311_pp73-manylinux_2_17_x86_64.manylinux2014_x86_64.whl   10,969 kB

However the manylinux arm job builds 13 wheels:

13 wheels produced in 22 minutes:
  python_flint-0.7.1-cp311-cp311-manylinux_2_28_aarch64.whl          11,292 kB
  python_flint-0.7.1-cp311-cp311-manylinux_2_31_armv7l.whl            8,070 kB
  python_flint-0.7.1-cp312-cp312-manylinux_2_28_aarch64.whl          11,200 kB
  python_flint-0.7.1-cp312-cp312-manylinux_2_31_armv7l.whl            8,022 kB
  python_flint-0.7.1-cp313-cp313-manylinux_2_28_aarch64.whl          11,186 kB
  python_flint-0.7.1-cp313-cp313-manylinux_2_31_armv7l.whl            8,013 kB
  python_flint-0.7.1-cp313-cp313t-manylinux_2_28_aarch64.whl         11,279 kB
  python_flint-0.7.1-cp313-cp313t-manylinux_2_31_armv7l.whl           7,990 kB
  python_flint-0.7.1-cp314-cp314-manylinux_2_28_aarch64.whl          11,231 kB
  python_flint-0.7.1-cp314-cp314-manylinux_2_31_armv7l.whl            7,986 kB
  python_flint-0.7.1-cp314-cp314t-manylinux_2_28_aarch64.whl         11,280 kB
  python_flint-0.7.1-cp314-cp314t-manylinux_2_31_armv7l.whl           7,991 kB
  python_flint-0.7.1-pp311-pypy311_pp73-manylinux_2_28_aarch64.whl   10,965 kB

It seems that what happens is that cibuildwheel uses a manylinux container to build all the non-pypy wheels but then launches a new Ubuntu container for the pypy wheels and then in that new container it builds not just the pypy whel but also new versions of the cpython wheels for armv7l.

The cibuildwheel configuration is at:
https://github.com/flintlib/python-flint/blob/31218dfd2f53d575f22181b0988a2486c201c7a7/.github/workflows/buildwheel.yml#L6-L59
And:
https://github.com/flintlib/python-flint/blob/31218dfd2f53d575f22181b0988a2486c201c7a7/pyproject.toml#L82-L115

Is this expected behaviour?

[oscarbenjamin]

In a separate PR (flintlib/python-flint#284) using cibuildwheel 2.23.2 the job works as expected:

5 wheels produced in 10 minutes:
  python_flint-0.7.1-cp311-cp311-manylinux_2_28_aarch64.whl          11,292 kB
  python_flint-0.7.1-cp312-cp312-manylinux_2_28_aarch64.whl          11,200 kB
  python_flint-0.7.1-cp313-cp313-manylinux_2_28_aarch64.whl          11,186 kB
  python_flint-0.7.1-cp313-cp313t-manylinux_2_28_aarch64.whl         11,279 kB
  python_flint-0.7.1-pp311-pypy311_pp73-manylinux_2_28_aarch64.whl   10,965 kB

[mayeut]

This is the expected behavior in v3.0.0b1 and the same behavior as on x86_64 by default, that is, build 64-bit and 32-bit wheels.
In this case, this translates to all aarch64 wheels in one container and all armv7l wheels in another container.

You should skip armv7l as is done for i686 in pyproject.toml if you don't want the armv7l wheels.

[oscarbenjamin]

Thanks. Okay, that makes sense. I will test that shortly.

I guess I got confused because the job succeeded until it got to the pypy wheel.

A different question then is why is there no pypy wheel for aarch64?

[oscarbenjamin]

A different question then is why is there no pypy wheel for aarch64?

Sorry there is a pypy wheel for aarch64 but there is not for armv7l. Is it just not available in that container?

[mayeut]

Is it just not available in that container?

There's no PyPy release for armv7l so no PyPy wheels (as seen in the table in README, you might have to scroll right to see armv7l).

[oscarbenjamin]

Okay that makes sense. It is all working now with cibuildwheel 3.0.0b1 in flintlib/python-flint#283 after adding *-manylinux_armv7l to skip:

[tool.cibuildwheel]
skip = "*-win32 *-manylinux_i686 *-manylinux_armv7l *-musllinux_*"

Thanks @mayeut for your help!