x86 wheels are built for macOS 11.0 when building with CIBW_ARCHS: x86_64 arm64

[nicholasjng]

Hello cibuildwheel community,

I am trying to build macOS wheels of a package for both macOS x86 and ARM64, using the CIBW_ARCHS option. I run on GitHub Actions' macos-10.15, and my subsequent wheel testing fails because a macosx_11_0 wheel is built for x86 (which is unsupported).

Correct me if I am wrong, but shouldn't the MACOSX_DEPLOYMENT_TARGET still be "10.9" for the x86 wheels, even when building arm64 wheels at the same time? I also explicitly set the target to 10.9, but it still ends up building macOS 11 wheels. I was able to find some issues on that environment variable, but nothing that looked quite like the problem here.

I think I am missing something about the macOS deployment configuration here, and wanted to get some direction before opening an issue. Thank you for your consideration.

[henryiii]

Do you have a link to the package? Sounds like possibly an issue with your setup. Normal setuptools, scikit-build, other?

[nicholasjng]

It's Google benchmark, where I'm currently contributing wheel CI in my free time. I am testing workflow setups here on the wheel_action branch in my fork:

https://github.com/nicholasjng/benchmark/tree/wheel-action

Here is the setup.py, using setuptools:

https://github.com/nicholasjng/benchmark/blob/wheel-action/setup.py

[henryiii]

It's a Bazel wrapper. Going to bet they didn't add the Bazel equivalent of https://github.com/pybind/cmake_example/blob/2440893c60ed2578fb127dc16e6b348fa0be92c1/setup.py#L94-L98 .

[nicholasjng]

Right on the money! When explicitly setting the minimum macOS target to 10.9 on x86 in bazel build, proper 10.9 wheels are built. Thank you so much for your help!