anchor.diff:  
       users.extraGroups.sddm.gid = config.ids.gids.sddm;
   
  +    services.dbus.packages = [ sddm.unwrapped ];
  +
  +    # To enable user switching, allow sddm to allocate TTYs/displays dynamically.
  +    services.xserver.tty = null;
  +    services.xserver.display = null;
     };
   }
  
positive.code:     #!/bin/sh
      ${cfg.stopScript}
    '';
  
  
    cfgFile = pkgs.writeText "sddm.conf" ''
      [General]
  
negative.code:     HideShells=/run/current-system/sw/bin/nologin
  
      [X11]
      MinimumVT=${toString (if xcfg.tty != null then xcfg.tty else 7)}
      ServerPath=${xserverWrapper}
      XephyrPath=${pkgs.xorg.xorgserver.out}/bin/Xephyr
      SessionCommand=${dmcfg.session.script}
  