. Default: Example: Declared by: Defined by: null '''' "" true false [ ] { = ; } (download of ) (build of ) https://github.com/NixOS/nixpkgs/blob/master/ https://github.com/NixOS/nixpkgs/blob// https://github.com/NixOS/nixops/blob//nix/ file:// <nixpkgs/> <nixops/>