{ config, lib, pkgs, ... }: { imports = [ ]; options.me = { yubikey.enable = lib.mkOption { type = lib.types.bool; default = false; example = true; description = "Whether we want to install yubikey."; }; }; config = lib.mkIf config.me.yubikey.enable ( lib.mkMerge [ { environment.systemPackages = with pkgs; [ yubikey-personalization yubikey-manager ]; } ] ); }