Comment 2 for bug 750149

StacktraceTop:
 raise (sig=6) at ../nptl/sysdeps/unix/sysv/linux/raise.c:64
 abort () at abort.c:92
 g_assertion_message (domain=<value optimized out>, file=<value optimized out>, line=<value optimized out>, func=0x7f863d6c51a0 "call_in_idle_cb", message=0x27f4e90 "assertion failed: (vtable != NULL && vtable->method_call != NULL)") at /build/buildd/glib2.0-2.28.5/./glib/gtestutils.c:1358
 g_assertion_message_expr (domain=0x7f863d6a6401 "GLib-GIO", file=0x7f863d6c32e0 "/build/buildd/glib2.0-2.28.5/./gio/gdbusconnection.c", line=4407, func=0x7f863d6c51a0 "call_in_idle_cb", expr=<value optimized out>) at /build/buildd/glib2.0-2.28.5/./glib/gtestutils.c:1369
 call_in_idle_cb (user_data=0x27b0240) at /build/buildd/glib2.0-2.28.5/./gio/gdbusconnection.c:4407