Checks fail for classes with immutable metaclasses

[shiftinv]

First of all, thank you for this neat tool!

I've been seeing issues with checking classes that have immutable metaclasses, or generally metaclasses that raise an exception in their __setattr__ (or __delattr__), due to this:

slotscheck/src/slotscheck/checks.py

Line 74 in 9a2cba3

t._SLOTSCHECK_POKE = 1 # type: ignore

This seems to be the case defined in the tests here:

slotscheck/tests/src/test_checks.py

Lines 41 to 47 in 9a2cba3

	class _RestrictiveMeta(type):
	def __setattr__(self, name, value) -> None:
	raise TypeError("BOOM!")
	class _UnsettableClass(metaclass=_RestrictiveMeta):
	pass

I'm not too familiar with the specifics of Python extensions, so I couldn't come up with any good solutions, but it would be nice if these types were supported as well.

edit: the second half of this answer may be useful? Seems like an implementation quirk though, so it would need some testing to make sure it's reliable :/

[ariebovenberg]

@shiftinv many thanks for this find! The answer in the link may not be 100% provably correct, but it's way better than the current check.

related: #8

In any case: I can implement this rather easily.

[shiftinv]

Awesome, thank you for the quick fix!