totem-video-thumbnailer crashes as of version 2.17.5:

> (process:21220): GStreamer-WARNING **: The GStreamer function gst_init_get_option_group() was
>         called, but the GLib threading system has not been initialised
>         yet, something that must happen before any other GLib function
>         is called. The application needs to be fixed accordingly, please
>         file a bug against this application.
>
> GThread-ERROR **: GThread system may only be initialized once.
> aborting...
> zsh: abort (core dumped)  totem-video-thumbnailer

The reason is probably that in totem-video-thumbnailer.c some g_* functions are called before g_thread_init(), which was introduced somewhere between 2.17.3 and 2.17.5:

> context = g_option_context_new ("Thumbnail movies");
> options = bacon_video_widget_get_option_group ();
> g_option_context_add_main_entries (context, entries, GETTEXT_PACKAGE);
> g_option_context_add_group (context, options);
>
> g_thread_init (NULL);

Since bacon_video_widget_get_option_group() is just a wrapper for gst_init_get_option_group() (which calls g_thread_init() internally) it should be this particular call that causes the second g_thread_init() to crash.

This should be fixed by either moving these g_* function calls below the g_thread_init() (which seems be the correct way) or by replacing the g_thread_init() call by something like the following:

> if (!g_thread_supported ()) g_thread_init (NULL);