Merge pull request #72959 from worldofpeace/gnome-flashback-systemd

nixos/gnome3: add gnome-flashback to systemd.packages

nixos/modules/services/x11/desktop-managers/gnome3.nix

@@ -184,6 +184,13 @@ in
         enableGnomeKeyring = true;
       };
 
+      systemd.packages = with pkgs.gnome3; [
+        gnome-flashback
+      ] ++ (map
+        (wm: gnome-flashback.mkSystemdTargetForWm {
+          inherit (wm) wmName;
+        }) cfg.flashback.customSessions);
+
       services.dbus.packages = [
         pkgs.gnome3.gnome-screensaver
       ];

pkgs/desktops/gnome-3/misc/gnome-flashback/default.nix

@@ -22,6 +22,7 @@
 , writeTextFile
 , writeShellScriptBin
 , xkeyboard_config
+, runCommand
 }:
 
 let
@@ -141,6 +142,13 @@ let
           DesktopNames=GNOME-Flashback;GNOME;
         '';
       };
+
+      mkSystemdTargetForWm = { wmName }:
+        runCommand "gnome-flashback-${wmName}.target" {} ''
+          mkdir -p $out/lib/systemd/user
+          cp "${gnome-flashback}/lib/systemd/user/gnome-session-x11@gnome-flashback-metacity.target" \
+            "$out/lib/systemd/user/gnome-session-x11@gnome-flashback-${wmName}.target"
+        '';
     };
 
     meta = with stdenv.lib; {