Nix derivation and nix store managed artifacts is a superior model to many language specific package managers (though the learning curve is non-trivial), we use it with Haskell extensively, for instance.
It was a very frustrating experience. A frustration which was led by the fact that i could tell how powerful Nixos was - if only i could grok it.
I love nix, my biggest gripe would be that the Nix language is dynamically typed...