Comment by JamesSwift

> In the Nixos world there isn't really a concept of a "binary/installation package" like in Debian or elsewhere. Everything can be rebuilt from source on any machine

Thats not actually the case. A derivation is just an abstract concept that combines a hash with a "thing". Here is an example [1] of a pre-compiled mono binary that gets downloaded and installed (after patching paths).

[1] - https://github.com/NixOS/nixpkgs/blob/0cbe9f69c234a7700596e9...