Detection of numpy capabilities (complex256)

[hmaarrfk]

Comment:

@conda-forge/h5py has been having trouble with detection of complex256 support on cross compiled platforms.

I'm curious if there is a good way to do this with cross python. For reference h5py upstream
https://github.com/h5py/h5py/blob/b4994d07aa9e07b231b759019b12a231c13d5558/setup_build.py#L132 (h5py version 3.12.1)

uses

import numpy
complex256_support = hasattr(numpy, 'complex256')

which will return true on "cross compiled", but our version of numpy on osx+arm doesn't support complex256.

This is causing issues.

Is there a better test we can recommend for upstream.

Any other recommendations welcome!