{ config, lib, pkgs, ... }: with lib; let cfg = config.services.xserver.windowManager.leftwm; in { ###### interface options = { services.xserver.windowManager.leftwm.enable = mkEnableOption "leftwm"; }; ###### implementation config = mkIf cfg.enable { services.xserver.windowManager.session = singleton { name = "leftwm"; start = '' ${pkgs.leftwm}/bin/leftwm & waitPID=$! ''; }; environment.systemPackages = [ pkgs.leftwm ]; }; }