I’m still a Nix beginner, and one thing I couldn’t figure out until recently was how to keep parts of my configuration.nix file under source control. My goal I’d like for my Nix configuration files to be modular and reusable, so depending on the system or flake, I can pull in only the configuration files I need. I’d like all my Nix configuration files to be under source control so that different systems can depend on different versions of any file so I don’t have to upgrade every system to the latest version of each configuration file at the same time.