Install gsettings schemas.

common-gui.nix

@@ -101,4 +101,21 @@
     agent.pinentryFlavor = "gnome3";
   };
 
+  # https://github.com/NixOS/nixpkgs/pull/54083
+  environment.extraSetup = ''
+    if [ -d  $out/share/gsettings-schemas/ ]; then
+      # Create the standard schemas directory
+      mkdir -p $out/share/glib-2.0/schemas
+      # symlink any schema files to the standard schema directory
+      for d in $out/share/gsettings-schemas/*; do
+        # Force symlink, in case there are duplicates
+        ln -fs $d/glib-2.0/schemas/*.xml $out/share/glib-2.0/schemas
+      done
+      # and compile them
+      if [ -w $out/share/glib-2.0/schemas ]; then
+        ${pkgs.glib.dev}/bin/glib-compile-schemas $out/share/glib-2.0/schemas
+      fi
+    fi
+  '';
+
 }