(gdb) bt
#0  0x0010dfc2 in tp_text_mixin_set_message_types (obj=0xf444) at text-mixin.c:271
#1  0x000035b6 in constructor (type=3221225472, n_props=3221225472, props=0xc0000000) at textchan-null.c:80
#2  0x001c645b in g_object_newv ()
#3  0x001c790c in g_object_new_valist ()
#4  0x001c7bbb in g_object_new ()
#5  0x00002913 in main (argc=1, argv=0xbffff42c) at channel-introspect.c:79