> not sure how it's relevant.

Well you said earlier that nothing I said works in practice for python packages. My only point is that it must work at some level in the python ecosystem, else the ecosystem would collapse.

Anyways, it sounds like you're unhappy that someone did a bad job packaging your application. That sucks. Elsewhere in this thread someone mentioned that there isn't a strict single version policy in nixpkgs, so this can probably be easily fixed. I'd suggest filing a bug in Nixpkgs.