Some Nix tools do this for Python, giving you separate tools for building libraries and applications. Overall, you're describing how Nix/Nixpkgs works today. >

Some Nix tools do this for Python, giving you separate tools for building libraries and applications. Overall, you're describing how Nix/Nixpkgs works today. > A library can be used together with other libraries and so cannot pin its own dependency versions (if all libraries did so there would conflicts everywhere) but instead can only specify constraints on its dependency versions (eg >=1.0.0). This is a Python defect. IIRC, for example, Node libraries can and do pin their dependencies without conflict, because Node has no problem using multiple versions of the same library in a process. Python can't do this. It could (there have been proofs of concept that make this work), but it doesn't.