Comment 2 for bug 1097889

StacktraceTop:
 g_type_check_instance (type_instance=type_instance@entry=0x1c49080) at /build/buildd/glib2.0-2.34.3/./gobject/gtype.c:4063
 g_signal_emitv (instance_and_params=instance_and_params@entry=0x1cdca60, signal_id=248, detail=0, return_value=return_value@entry=0x7fff7cac0960) at /build/buildd/glib2.0-2.34.3/./gobject/gsignal.c:2957
 pygobject_emit (self=<optimized out>, args=0x7f673850dfa0) at ../../../gi/_gobject/pygobject.c:1946
 ext_do_call (nk=0, na=<optimized out>, flags=<optimized out>, pp_stack=0x7fff7cac0bd0, func=0x7f67380bf2d8) at ../Python/ceval.c:4374
 PyEval_EvalFrameEx (f=f@entry=0x1ce3210, throwflag=throwflag@entry=0) at ../Python/ceval.c:2720