Setup In one of the projects, I use a pinned version of nixpkgs based on miso. There are two advantages to that, one is that I know that miso builds with that version, and the second one is that I can take advantage of miso’s cachix cache and not compile everything from scratch. In the most basic form, it looks like this. File nixpkgs.nix: let bootstrap = import <nixpkgs> {}; misoTarball = bootstrap.