Merge pull request #208060 from chpatrick/fix-gnome-flashback-systemd

gnome.gnome-flashback: fix crash on start due to not finding .desktops

nixos/tests/all-tests.nix

@@ -240,6 +240,7 @@ in {
   gitolite-fcgiwrap = handleTest ./gitolite-fcgiwrap.nix {};
   glusterfs = handleTest ./glusterfs.nix {};
   gnome = handleTest ./gnome.nix {};
+  gnome-flashback = handleTest ./gnome-flashback.nix {};
   gnome-xorg = handleTest ./gnome-xorg.nix {};
   go-neb = handleTest ./go-neb.nix {};
   gobgpd = handleTest ./gobgpd.nix {};

nixos/tests/gnome-flashback.nix

@@ -0,0 +1,51 @@
+import ./make-test-python.nix ({ pkgs, lib, ...} : {
+  name = "gnome-flashback";
+  meta = with lib; {
+    maintainers = teams.gnome.members ++ [ maintainers.chpatrick ];
+  };
+
+  nodes.machine = { nodes, ... }: let
+    user = nodes.machine.config.users.users.alice;
+  in
+
+    { imports = [ ./common/user-account.nix ];
+
+      services.xserver.enable = true;
+
+      services.xserver.displayManager = {
+        gdm.enable = true;
+        gdm.debug = true;
+        autoLogin = {
+          enable = true;
+          user = user.name;
+        };
+      };
+
+      services.xserver.desktopManager.gnome.enable = true;
+      services.xserver.desktopManager.gnome.debug = true;
+      services.xserver.desktopManager.gnome.flashback.enableMetacity = true;
+      services.xserver.displayManager.defaultSession = "gnome-flashback-metacity";
+    };
+
+  testScript = { nodes, ... }: let
+    user = nodes.machine.config.users.users.alice;
+    uid = toString user.uid;
+    xauthority = "/run/user/${uid}/gdm/Xauthority";
+  in ''
+      with subtest("Login to GNOME Flashback with GDM"):
+          machine.wait_for_x()
+          # Wait for alice to be logged in"
+          machine.wait_for_unit("default.target", "${user.name}")
+          machine.wait_for_file("${xauthority}")
+          machine.succeed("xauth merge ${xauthority}")
+          # Check that logging in has given the user ownership of devices
+          assert "alice" in machine.succeed("getfacl -p /dev/snd/timer")
+
+      with subtest("Wait for Metacity"):
+          machine.wait_until_succeeds(
+              "pgrep metacity"
+          )
+          machine.sleep(20)
+          machine.screenshot("screen")
+    '';
+})

pkgs/desktops/gnome/misc/gnome-flashback/default.nix

@@ -180,9 +180,11 @@ let
             dontWrapGApps = true; # We want to do the wrapping ourselves.
 
             # gnome-flashback and gnome-panel need to be added to XDG_DATA_DIRS so that their .desktop files can be found by gnome-session.
+            # We need to pass the --builtin flag so that gnome-session invokes gnome-session-binary instead of systemd.
+            # If systemd is used, it doesn't use the environment we set up here and so it can't find the .desktop files.
             preFixup = ''
               makeWrapper ${gnome-session}/bin/gnome-session $out \
-                --add-flags "--session=gnome-flashback-${wmName}" \
+                --add-flags "--session=gnome-flashback-${wmName} --builtin" \
                 --set-default XDG_CURRENT_DESKTOP 'GNOME-Flashback:GNOME' \
                 --prefix XDG_DATA_DIRS : '${lib.makeSearchPath "share" ([ wmApplication gnomeSession gnome-flashback ] ++ lib.optional enableGnomePanel gnome-panel)}' \
                 "''${gappsWrapperArgs[@]}" \