xapp: Wrap xapp-sn-watcher

This is an executable.

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";