In udisksclient.c: When this code fails:

  client->object_manager = udisks_object_manager_client_new_for_bus_sync (G_BUS_TYPE_SYSTEM,
                                                                          G_DBUS_OBJECT_MANAGER_CLIENT_FLAGS_NONE,
                                                                          "org.freedesktop.UDisks2",
                                                                          "/org/freedesktop/UDisks2",
                                                                          cancellable,
                                                                          &client->initialization_error);
  if (client->object_manager == NULL)
    goto out;

Then this aborts:

  g_signal_handlers_disconnect_by_func (client->object_manager,
                                        G_CALLBACK (on_object_added),
                                        client);

Along with the lines following it.