[BUG] Passing custom arg is not possible via PEP517 backends about python-frozendict

[Marco-Sulla]

Yes, it's in the TODO list:

Ponder to remove the py wheel and make the C Extension optional

Not very difficult to do:

myextension = Extension(
    "myextension",
    ["myextension.c"],
    optional=os.environ.get('CIBUILDWHEEL', '0') != '1',
)

https://cibuildwheel.readthedocs.io/en/stable/faq/#optional-extensions

[Marco-Sulla]

It should be fixed with the new release:
https://github.com/Marco-Sulla/python-frozendict/releases/tag/v2.3.5

Can you confirm it?

[mgorny]

It's not fixed. We still can't tell it not to try building the C extension for Python 3.11. Furthermore, now we need to explicitly pass CIBUILDWHEEL=1 to ensure that it silently doesn't ignore unrelated build failures on other Python versions.

[Marco-Sulla]

What's the problem of trying to build the C Extension for Python 3.11?

[Marco-Sulla]

The problem here is pip and not supported platforms.

If someone wants to install the module for an architecture X and the arch X binary is not present on Pypi, pip downloads and install the pure py wheel if present. It does not try to install the sdist package, even if present.

On the contrary, if an sdist package is present and a wheel is not present, it tries to compile the sdist. But if so, the C Extension must be optional by default, or if the sdist install fails, no module will be installed.

This is much more simple for the end user, and a bit more complicated for devs. But I'm confident that devs are much more expert and it's quite trivial for them to add an env variable. I have to do the same on Conda.

Anyway, I could change how CIBUILDWHEEL works now. If 1, the Extension will be added as mandatory. If zero, the module will be compiled with no extension. If None, the above default behavior acts (Ext enabled but optional).

[mgorny]

I think something akin #69 is the best option where the user (or packager) can easily say "I want the C extension if it's supported on my interpreter" and the package takes care of "knowing" which Python versions are supported and which are not.

[Marco-Sulla]

#69 is not about this, but it's a good solution for your case, since it checks if a dir with C source files exists. If not, the py wheel is produced.

Since no src dir exists for Python 3.11, the PR will enable for 3.11 the py package by default.

This has also a side benefit to have a pure py package on Conda without trouble.

I'll accept the PR.

[mgorny]

Thank you.

[Marco-Sulla]

Released in 2.3.6, let me know if it's all OK.

[mgorny]

Thanks, it seems to work fine for us!