Comment 2 for bug 1051629

StacktraceTop:
 __GI___libc_free (mem=0x2f04) at malloc.c:2968
 g_callable_info_free_closure (callable_info=<optimized out>, closure=0x17a4a30) at girepository/girffi.c:409
 _pygi_invoke_closure_free (data=0x1db98a0) at /build/buildd/pygobject-3.3.91/gi/pygi-closure.c:526
 g_slist_foreach (list=<optimized out>, list@entry=0x7f7f5800b630, func=func@entry=0x7f7f847fe150 <_pygi_invoke_closure_free>, user_data=user_data@entry=0x0) at /build/buildd/glib2.0-2.33.12/./glib/gslist.c:894
 g_slist_free_full (list=0x7f7f5800b630, free_func=free_func@entry=0x7f7f847fe150 <_pygi_invoke_closure_free>) at /build/buildd/glib2.0-2.33.12/./glib/gslist.c:177