macOS wheels get wrongly tagged as universal2 #586

On macOS when building a wheel of python-ldap, I get one that carries the universal2 tag, which marks it as working on both x86 and ARM: python_ldap-3.4.4-cp313-cp313-macosx_10_13_universal2.whl

Unfortunately, it is not, and when a package installer caches the built wheel, it poisons its own cache and installing it on the wrong architecture creates a rather opaque error:

.venv/lib/python3.13/site-packages/ldap/__init__.py:34: in <module>
    import _ldap
E   ImportError: dynamic module does not define module export function (PyInit__ldap)

This means I have to clear the cache for python-ldap whenever I switch projects that use a different architecture (e.g., if I want to run uv lock --upgrade on both).

The uv folks told me this is a packaging problem that has to be fixed within the project itself.

I have attached the build log, because it's too long for inline copy-paste: build.log

Note the linker warnings: ld: warning: ignoring file 'build/temp.macosx-10.13-universal2-cpython-313/Modules/common.o': found architecture 'arm64', required architecture 'x86_64'

I ran the build with uvx --from build pyproject-build, i.e. the official PyPA builder.