Windows fatal exception when running test suite under PyCharm

[gdementen]

After my current work to squash all warnings (#936 and many others), there is still one oddity. When running the test suite under PyCharm a few tests generate "Windows fatal exception: code 0xXYZ".

AFAICT, these are harmless. All these errors seem to be related to xlwings/COM stuff and only happen when running the whole test suite, and not individual tests, so I suspect it's because the test suite hammers the COM server at a rate it cannot cope with.

I thought xlwings shielded us from such problems (and maybe it does and this is just the error message which shouldn't be displayed?) but maybe this is a subtle variation of xlwings/xlwings#468.

I also noticed they seem to all be related to writing to several cells at a time. In a few tests, I tried replacing the "write range in one go" by writing to each cell individually and the error disappeared for that test.

Finally, I really don't understand why I get those errors when running under PyCharm and not when running pytest directly in a console.

[gdementen]

PS: I opened this issue not in the hope we fix it anytime soon, but to do a brain dump of all the small bits of information I managed to get about this strange problem.