(gdb) bt
#0  clutter_actor_queue_relayout (self=0x8c2020) at ../../../clutter/clutter-actor.c:4985
#1  0x00007ffff7959d77 in clutter_texture_set_cogl_texture (texture=0x8c2020, cogl_tex=<value optimized out>)
    at ../../../clutter/clutter-texture.c:1270
#2  0x00007ffff7bd7436 in clutter_gst_yv12_upload (sink=<value optimized out>, buffer=0x7fffe4013710)
    at clutter-gst-video-sink.c:431
#3  0x00007ffff7bd68f4 in clutter_gst_video_sink_idle_func (data=<value optimized out>)
    at clutter-gst-video-sink.c:915
#4  0x00007ffff7942d8f in clutter_threads_dispatch (data=0x9e4880) at ../../../clutter/clutter-main.c:1059
#5  0x00007ffff507a342 in g_main_context_dispatch () from /lib/libglib-2.0.so.0
#6  0x00007ffff507e2a8 in ?? () from /lib/libglib-2.0.so.0
#7  0x00007ffff507e7b5 in g_main_loop_run () from /lib/libglib-2.0.so.0
#8  0x00007ffff79430bd in clutter_main () at ../../../clutter/clutter-main.c:939
#9  0x000000000040640c in main (argc=2, argv=0x7fffffffda08) at snappy.c:169