Python 2.0 selected when installing with zlib

[benmoss]

Checks

• [X] I have checked that this issue has not already been reported.

• [X] I have confirmed this bug exists on the latest version of pixi, using pixi --version.

Reproducible example

On an osx-arm64 machine with pixi 0.20.1

pixi init --platform linux-64 --platform osx-arm64
pixi add python zlib

Issue description

It picks Python 2.0 for linux-64 and Python 3.12.3 for osx-arm64

Expected behavior

I think it should pick 3.12.3 for both

[ruben-arts]

That is an interesting find! Our solver tries to use the highest versions but this time it got exactly what you don't want.

python 3.x.x has a dependency of libzlib of <=1.2.13,<1.3.0a0 but for some reason the solver chose to pick libz 1.3.1 before the python version.

@baszalmstra Do you know if this is a issue in pixi or this is is part of resolvo. And you we could avoid this?

A quick fix would be to limit zlib or python yourself. E.g. pixi add "python>3.7" zlib

[baszalmstra]

Im not sure what to do here. Packages can have different versions on different platforms. This is definitely an extreme example but it is the only correct one. (Btw I retried this specific example and it resolves both pythons to 3.x now).

Im going to close this issue for now because I don't think its actionable.