Comment 17 for bug 1154049

There's a similar issue in thunar, when starting thunar gtk2 as deamon and than starting thunar gtk3 the same error occurs. ( That's what I currently try to fix )

So far I isolated the problem to happen when "g_application_run" is called ... however thunar exits before the passed method is called.

With fetching the error of "g_application_register" it is possible to react to the bug .. e.g. killing the daemon ? Gracefull shutdown with graphical error ? Not sure yet what would be the best workaround fix.

Possibly it helps for your seahorse bug. Here the related code:

  GError *error = NULL;
  ...
  if( g_application_register (G_APPLICATION (application), NULL, &error))
    {
      printf("Is already registered\n");
    }
  if (error != NULL)
    {
      printf ("Error happened: %s\n", error->message);
      // Print some graphical warning ? Kill the daemon ?
      g_error_free (error);
    }

  g_application_run (G_APPLICATION (application), argc, argv);