{ config, pkgs, unstable, ... }: { nixpkgs.config.packageOverrides = pkgs: { canon-cups-ufr2 = unstable.canon-cups-ufr2; }; services.printing = { enable = true; drivers = [ pkgs.canon-cups-ufr2 ]; }; environment.systemPackages = with pkgs; [ canon-cups-ufr2 cups ]; }