So maybe I'm spoiled by linux package managers, where you tell it to "upgrade" and things continue to work... to me that is just a natural expectation.

Well, it seems the python package manager (pip) will happily upgrade all your project's required dependencies, but not your optional dependencies... yet the old (incompatible) version is still visible at runtime.

Consequently, it seems to be an excepted norm in the python world that things may break after a "pip upgrade", at least on a single tool.

How do python devs put up with this? Apparently there are a bunch of hacks scattered across countless projects to test at runtime for incompatible deps, even though they have already dutifully specified the compatible version in the dependencies list.

What a mess.