#0  gst_mini_object_unlock (object=0x7f876a02c010, flags=flags@entry=GST_LOCK_FLAG_EXCLUSIVE) at gstminiobject.c:241
  [Error: gstminiobject.c was not found in source tree]
#1  0x00007f87810d3d41 in _gst_buffer_free (buffer=0x7f8760032230) at gstbuffer.c:530
  [Error: gstbuffer.c was not found in source tree]
#2  0x00007f87700712b0 in gst_buffer_unref (buf=<optimized out>) at /usr/include/gstreamer-1.0/gst/gstbuffer.h:350
  [Error: /usr/include/gstreamer-1.0/gst/gstbuffer.h was not found in source tree]
#3  gst_qtdemux_loop_state_header (qtdemux=0x7f876006a130) at qtdemux.c:2785
  [Error: qtdemux.c was not found in source tree]
#4  gst_qtdemux_loop (pad=0x7f878455d2a0) at qtdemux.c:3872
  [Error: qtdemux.c was not found in source tree]
#5  0x00007f878112cc31 in gst_task_func (task=0x7f878443f6c0) at gsttask.c:316
  [Error: gsttask.c was not found in source tree]
#6  0x00007f8780bc1e32 in g_thread_pool_thread_proxy (data=<optimized out>) at /build/buildd/glib2.0-2.35.4/./glib/gthreadpool.c:309
  [Error: /build/buildd/glib2.0-2.35.4/./glib/gthreadpool.c was not found in source tree]
#7  0x00007f8780bc15f5 in g_thread_proxy (data=0x7f8760067230) at /build/buildd/glib2.0-2.35.4/./glib/gthread.c:798
  [Error: /build/buildd/glib2.0-2.35.4/./glib/gthread.c was not found in source tree]
#8  0x00007f878063ef9f in start_thread (arg=0x7f876abd7700) at pthread_create.c:311
  [Error: pthread_create.c was not found in source tree]
#9  0x00007f878036c0cd in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:114
  [Error: ../sysdeps/unix/sysv/linux/x86_64/clone.S was not found in source tree]