PyPy support for macOS 11

[henryiii]

Should we mention in the docs that macOS 11 (which is now the default for macos-latest, I believe) is not supported by PyPy yet? Also would be curious if v7.3.6rc1 fixes the issue, and/or supports more architectures like AS or PowerPC. CC @mattip

[mattip]

I am pretty sure PyPy runs on macOS 11 on x86_64, not on arm64 and still defines MACOSX_DEPLOYMENT_TARGET = 10.6. PyPy supports linux on PowerPC, but I would not recommend people add it to their CI or build wheels for it, as it is not very popular and CI runs on travis can be flaky. What is AS ?

[henryiii]

Ah, so this is invalid now?

cibuildwheel/cibuildwheel/macos.py

Lines 98 to 112 in e60ece0

	if any(c.identifier.startswith("pp") for c in python_configurations):
	# pypy doesn't work on macOS 11 yet
	# See https://foss.heptapod.net/pypy/pypy/-/issues/3314
	log.warning(
	unwrap(
	"""
	PyPy is currently unsupported when building on macOS 11. To build macOS PyPy
	wheels, build on an older OS, such as macOS 10.15. To silence this warning,
	deselect PyPy by adding "pp*-macosx*" to your CIBW_SKIP option.
	"""
	)
	)
	python_configurations = [
	c for c in python_configurations if not c.identifier.startswith("pp")
	]

And AS is Apple Silicon, short for macOS+Arm64, as opposed to linux ARM. It would be really nice to be supported. I have a AS box if you need testing once in a while.

If it's not available in the manylinux images, then it's really hard to build for PowerPC. Some of the newer HPC systems are PowerPC clusters now, so having access to it is nice (and alternative archs are never on by default). Also, GHA emulation works most of the time for building, you don't have to use Travis, it's just slow. There's also a cross compile project.

[henryiii]

If our tests are running on 11 now, why is this not failing tests? Hmm.

[mattip]

The JIT needs work to support Apple Silicon (M1). The hardware is just different enough from aarch64 that it will not work.