The missing link for me is nix-copy-closure, which I learned about from a post by mitchellh: https://mitchellh.com/writing/nix-with-dockerfiles

conceptually a game changer for me. In practice it's far from a silver bullet (because every language prefers its own package management so you still have to manage those), but when it works it's quite magical.

You can patchelf to link to the host system libraries instead, or some projects can statically compile (inc musl) with less drama than usual, since your cross compilation toolchain can be part of your nix-shell.

Isn't this what you want? You are reliably linking to the specific dynamic libraries you are compiling against.

Or was the issue that you expected them to be portable? Or use commonly known dynamic library locations?

Sometimes it matters, many times not.

For example I tried to run pip install yesterday on MemGPT on Nix.

It failed with a C++ error because they use miniconda.

I just created a nix shell with python, pip, etc and ran the pip install command.

Things work fine.