We want to remove all exposure of DBusGLib types in our introspected API (don't want to depend on the unshipped DBusGLib-1.0.gir). Thus we need to (skip) a property that we don't want to expose.

  /**
   * TpProxy:dbus-connection: (skip)
   *
   * The D-Bus connection for this object. Read-only except during
   * construction.
   */
  param_spec = g_param_spec_boxed ("dbus-connection", "D-Bus connection",
      "The D-Bus connection used by this object", DBUS_TYPE_G_CONNECTION,
      G_PARAM_CONSTRUCT_ONLY | G_PARAM_READWRITE |
      G_PARAM_STATIC_NAME | G_PARAM_STATIC_BLURB | G_PARAM_STATIC_NICK);
  g_object_class_install_property (object_class, PROP_DBUS_CONNECTION,
      param_spec);

Unfortunately this still ends up in the introspected output.