`_osx_support.get_platform_osx()` does not always return the minor release number

[keleftheriou]

_osx_support.get_platform_osx(), particularly when called from sysconfig.get_platform(), might not return the minor release number. This seems to be because the MACOSX_DEPLOYMENT_TARGET environment variable will be used instead (if present), which may or may not include a minor version number.

E.g. on macOS 12.6 with MACOSX_DEPLOYMENT_TARGET=12:

>>> _osx_support.get_platform_osx({}, "", "", "")
('macosx', '12.6', '')
>>> _osx_support.get_platform_osx(sysconfig.get_config_vars(), "", "", "")
('macosx', '12', '')

Perhaps release = macver could be switched to release = macrelease here so that the internal _get_system_version() will be used instead?

Linked PRs

• gh-102362: Fix macOS version number in result of sysconfig.get_platform() #112942
• [3.12] gh-102362: Fix macOS version number in result of sysconfig.get_platform() (GH-112942) #113264
• [3.11] gh-102362: Fix macOS version number in result of sysconfig.get_platform() (GH-112942) #113265

[terryjreedy]

It seems to me that TARGET without minor release suggests that minor release number is not relevant. I have no thought on the other case.

[keleftheriou]

Agreed, it shouldn't be relevant. The reason I looked into this is because a wheel file I'm generating is producing this error: [REDACTED]_macosx_12_arm64.whl is not a supported wheel on this platform., and the filename is derived from sysconfig.get_platform().

If I manually rename it the file to add e.g. _0 after macosx_12 it works fine, and I was looking to identify the root cause of the issue. Perhaps always including a zero for the minor version returned from get_platform_osx() would be more consistent.

[keleftheriou]

May be related: pypa/wheel#385 (comment)

[ronaldoussoren]

I've added a PR that will add '.0' to the version when MACOSX_DEPLOYMENT_TARGET is set to just a major version.

The PR is labelled for back port to 3.11 and 3.12, but I'm not sure if this is a change that is suitable for back ports.

• 👎/👍: This doesn't affect our installers at all as those get build with 10.9 as the deployment target
• 👍: This fixes an inconsistency in the result from sysconfig.get_platform() w.r.t. expectations from pip/platform
• 👎: The fix likely isn't necessary for build tooling because, in particular, the wheel project already contains a workaround for this
• It is hard to gauge whether or not this negatively impact existing code (e.g. code that expects that the version exactly matches the deployment target).

[ronaldoussoren]

@ned-deily, what's your opionion on this (both the change to make sure that the platform version includes at least a major and minor version and back porting this change)?

[ned-deily]

I think this is a long-standing bug, ever since Apple changed the semantics of macOS release numbers with macOS 11, and this should be the least-disruptive fix for it. The only gotcha I can think of is if the standard lib _osx_support isn't being called, perhaps by a distutils replacement. We could consider in addition changing configure.ac to do something similar if MACOSX_DEPLOYMENT_TARGET defaults to only a major version, but not if explicitly set by a variable. Again, as far as backporting, perhaps just to 3.12 to start?