xdg-desktop-portal-xapp: Fix crashes on non-Cinnamon desktops (#457570)

pkgs/by-name/xa/xapp/package.nix

@@ -96,6 +96,10 @@ stdenv.mkDerivation rec {
   # Fix gtk3 module target dir. Proper upstream solution should be using define_variable.
   env.PKG_CONFIG_GTK__3_0_LIBDIR = "${placeholder "out"}/lib";
 
+  preFixup = ''
+    wrapGApp $out/lib/xapps/xapp-sn-watcher
+  '';
+
   meta = with lib; {
     homepage = "https://github.com/linuxmint/xapp";
     description = "Cross-desktop libraries and common resources";

pkgs/by-name/xd/xdg-desktop-portal-xapp/package.nix

@@ -11,8 +11,8 @@
   gtk3,
   gsettings-desktop-schemas,
   mate,
-  xdg-desktop-portal,
   xapp,
+  xdg-desktop-portal,
 }:
 
 stdenv.mkDerivation rec {
@@ -39,6 +39,7 @@ stdenv.mkDerivation rec {
     gtk3
     gsettings-desktop-schemas # org.gnome.system.location
     mate.mate-desktop # org.mate.background
+    xapp # org.x.apps.portal
     xdg-desktop-portal
   ];