xserver: qtile as desktopManager

nixos/modules/services/x11/desktop-managers/default.nix

@@ -19,7 +19,7 @@ in
   # E.g., if KDE is enabled, it supersedes xterm.
   imports = [
     ./none.nix ./xterm.nix ./xfce.nix ./kde4.nix ./kde5.nix
-    ./e19.nix ./gnome3.nix ./kodi.nix
+    ./e19.nix ./gnome3.nix ./kodi.nix ./qtile.nix
   ];
 
   options = {

nixos/modules/services/x11/desktop-managers/qtile.nix

@@ -0,0 +1,25 @@
+{ config, lib, pkgs, ... }:
+
+with lib;
+
+let
+  cfg = config.services.xserver.desktopManager.qtile;
+in
+
+{
+  options = {
+    services.xserver.windowManager.qtile.enable = mkEnableOption "qtile";
+  };
+
+  config = mkIf cfg.enable {
+    services.xserver.desktopManager.session = [{
+      name = "qtile";
+      start = ''
+        ${pkgs.qtile}/bin/qtile
+        waitPID=$!
+      '';
+    }];
+    
+    environment.systemPackages = [ pkgs.qtile ];
+  };
+}