[threeducks]

Not sure if that counts, but if you import both matplotlib and OpenCV at once, there is a good chance of a crash due to conflicting PyQt binaries: https://github.com/matplotlib/matplotlib/issues/29139

But I agree that observable side effects are generally pretty rare. And apparently, both libraries are not even in the top 100 packages, depending on how you count. It looks like those spots are all taken by libraries used in uncached, wasteful CI workflows: https://hugovk.github.io/top-pypi-packages/

[kstrauser]

Oof. That doesn't count in my opinion. The conflict is unfortunate, but it's not because either package is trying to modify other code. That is, the error is a side effect of how loading multiple libs into the interpret works. In theory, at least, you could fix those bugs without modifying the packages' behavior at all.

But still a bummer, to be sure. It's easy enough for me to say it doesn't count when I haven't been affected by it.