RLS/BLD: use native Apple Silicon macOS for arm64 wheels; remove universal2

[mwtoews]

Use native Apple Silicon macOS runners (described here) to build arm64 wheels.

Also, remove universal2 wheels, since I think it's fine to have separate x86_64 builds for macOS.

[mwtoews]

Up to @jorisvandenbossche to decide about these changes for the upcoming maintenance release version 2.0.3 described in #1742

I'm working on a separate PR for main.

[jorisvandenbossche]

It's still showing the same warning / not actually running tests:

Warning: While cibuildwheel can build CPython 3.8 universal2/arm64 wheels, we cannot test the arm64 part of them, even when running on an Apple Silicon machine. This is because we use the x86_64 installer of CPython 3.8. See the discussion in pypa/cibuildwheel#1169 for the details. To silence this warning, set CIBW_TEST_SKIP: "cp38-macosx_*:arm64".

[jorisvandenbossche]

(I think it is also fine to directly target this PR to main, can still backport the eventual commit to 2.0.x if we want)

[mwtoews]

Switched to main and attempted to silence the issue with cibuildwheel and CPython 3.8 universal2/arm64 wheels. Note that warning is a new one not shown before. The older warnings related to cross-compiling and testing are now gone.

[coveralls]

Pull Request Test Coverage Report for Build 7884170432

Details

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall first build on maint-2.0-macos-14 at 88.076%

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Totals
Change from base Build 7874085015:	88.1%
Covered Lines:	2600
Relevant Lines:	2952

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💛 - Coveralls

[mwtoews]

Warnings all cleared up now, ready for final review.

I should elaborate more on why to remove universal2. They are nearly twice the size, since they contain both x86_64 and arm64. E.g. with the shapely 2.0.2 files:

$ file universal2/shapely/_geos.cpython-39-darwin.so 
universal2/shapely/_geos.cpython-39-darwin.so: Mach-O universal binary with 2 architectures: [x86_64:Mach-O 64-bit x86_64 bundle, flags:<NOUNDEFS|DYLDLINK|TWOLEVEL>] [arm64:Mach-O 64-bit arm64 bundle, flags:<NOUNDEFS|DYLDLINK|TWOLEVEL>]

which is cool, but there are individual wheels for each architecture, so pip should be able to fetch the correct built wheel for the host platform. But also be warned that I'm not a macOS user, so I don't have any direct experience with this stuff.

[martinfleis]

Do you want me to test something here? I have access to both M1 and Intel Mac.

[mwtoews]

@martinfleis My main curiosity is with pip install --dry-run --force shapely==2.0.2, which binary wheel is selected? universal2 or arm64?

[martinfleis]

That would pull arm64, while on M1.

[jorisvandenbossche]

I should elaborate more on why to remove universal2. They are nearly twice the size, since they contain both x86_64 and arm64

Yes, certainly on board with that. In most other projects where I am involved in, we also dropped the universal wheels the last years (eg pandas, and also numpy did the same I see)

[jorisvandenbossche]

Thanks, looks good!