Is forking nixpkgs the only way of building new packages?

[jtojnar]

What shall I do if I want to add a package, but do not want to touch nixpkgs tree?

It is perfectly fine to just inline the package definition into environment.systemPackages in your configuration.nix: # configuration.nix { pkgs }: { environment.systemPackages = [ (with pkgs; stdenv.mkDerivations { # … }) ]; } or if you prefer slightly cleaner # configuration.nix { pkgs }: { environment.systemPackages = let mypkg = (with pkgs; stdenv.mkDerivations { # … }); in [ mypkg ]; } Or if you want to pass it to multiple option…