nixos/plasma: use upstream xsession/wayland files

nixos/modules/services/x11/desktop-managers/plasma5.nix

@@ -136,9 +136,6 @@ let
           fi
       fi
 
-    ''
-    + ''
-      exec "${startplasma-x11}"
     '';
 
 in
@@ -183,6 +180,7 @@ in
 
   config = mkMerge [
     (mkIf cfg.enable {
+
       # Seed our configuration into nixos-generate-config
       system.nixos-generate-config.desktopConfiguration = [''
         # Enable the Plasma 5 Desktop Environment.
@@ -190,11 +188,7 @@ in
         services.xserver.desktopManager.plasma5.enable = true;
       ''];
 
-      services.xserver.desktopManager.session = singleton {
-        name = "plasma5";
-        bgSupport = true;
-        start = startplasma;
-      };
+      services.xserver.displayManager.sessionPackages = [ pkgs.libsForQt5.plasma5.plasma-workspace ];
 
       security.wrappers = {
         kcheckpass =
@@ -389,6 +383,7 @@ in
 
       # Update the start menu for each user that is currently logged in
       system.userActivationScripts.plasmaSetup = activationScript;
+      services.xserver.displayManager.setupCommands = startplasma;
 
       nixpkgs.config.firefox.enablePlasmaBrowserIntegration = true;
     })

nixos/tests/plasma5.nix

@@ -12,7 +12,7 @@ import ./make-test-python.nix ({ pkgs, ...} :
     imports = [ ./common/user-account.nix ];
     services.xserver.enable = true;
     services.xserver.displayManager.sddm.enable = true;
-    services.xserver.displayManager.defaultSession = "plasma5";
+    services.xserver.displayManager.defaultSession = "plasma";
     services.xserver.desktopManager.plasma5.enable = true;
     services.xserver.displayManager.autoLogin = {
       enable = true;

pkgs/desktops/plasma-5/plasma-workspace/default.nix

@@ -24,6 +24,7 @@ let inherit (lib) getBin getLib; in
 
 mkDerivation {
   name = "plasma-workspace";
+  passthru.providedSessions = [ "plasma" "plasmawayland" ];
 
   nativeBuildInputs = [ extra-cmake-modules kdoctools ];
   buildInputs = [