pyxem/kikuchipy test suite segmentation fault

[ericpre]

In hyperspy/hyperspy-extensions-list#56, I couldn't get the test suites of pyxem and kikuchipy to run without segmentation fault when orix (and dependencies) is installed using packages from pypi.org.

Installing orix from conda-forge work as a workaround.

[hakonanes]

Thanks. Will try to dig out the offending Numba functions from the test logs.

[hakonanes]

Highly related to #526, so closing.

[ericpre]

I think that this segmentation fault was different from the test failure mentioned in #526, because running the test suite was crashing the python process as opposed to a test that fails with a failing assertion and the test suite fully run.

Anyway, I tried to reproduce again and it didn't get the same issue (now pyxem works fine but kikuchipy is still crashing with a segmentation fault). I narrowed down to an issue with pyvista/qt6/qt5 and I suspect that installing orix first helped as workaround because of dependencies resolution - swaping matplotlib to matplotlib-base in the orix feedstock may also explain why I can't reproduce the original issue.

The issue is mostly likely that kikuchipy can import pyvista (and qt6) which cause the segmentation fault if qt5 was already imported through matplotlib or others, in which case, it will be related to pyxem/kikuchipy#715.

Still not clearly, why pyxem had the segmentation fault (which is why I originally suspected orix), possibly ffmpeg or similar is import pyqt, etc. or something to do with setting matplotlib backend when running the test suite...