ENH: Allow NPY_PKG_CONFIG_PATH environment variable override - #14495

This needs to be documented somewhere, maybe ./doc/source/reference/distutils.rst. I'm not familiar with this problem, but there are also functions like add_npy_pkg_config that might be relevant, have you investigated them?

I think tests aren't required for this, but docstring updates would indeed be nice, plus perhaps a mention in a separate place in the distutils guide.

I'd suggest a note in the get_npy_pkg_dir docstring, as well as in https://numpy.org/devdocs/reference/distutils.html#numpy.distutils.misc_util.Configuration.add_npy_pkg_config. The Notes section of the latter talks about standard and in-place builds. Cross-compilation can be mentioned there.

Other than that, change LGTM.

I don't see how I can meaninfully add something to ./doc/source/reference/distutils.rst about this.
I have added to docstrings for both add_npy_pkg_config() and get_npy_pkg_dir(). I do think that the addition to add_npy_pkg_config() docstring is a bit out of place, but if you like it there, it is fine with me.

I don't have any desire to or idea for how to add support for NPY_PKG_CONFIG_PATH to add_npy_pkg_config().

don't see how I can meaninfully add something to ./doc/source/reference/distutils.rst about this.

Agreed. Would be nice to have something there about cross-compiling in general, and then this envvar would fall under that. But given that we don't have it, there's no good place to add anything to in that guide. What you added in the docstring is already quite nice.

I have added to docstrings for both add_npy_pkg_config() and get_npy_pkg_dir(). I do think that the addition to add_npy_pkg_config() docstring is a bit out of place, but if you like it there, it is fine with me.

It's nice content to have, and it can be found when people search the package for "cross compiling". So let's worry about the rest whenever someone writes up a longer story about cross-compiling.

I don't have any desire to or idea for how to add support for NPY_PKG_CONFIG_PATH to add_npy_pkg_config().

agreed. that's not what I meant.

Merged, thanks @esben!