Comment 2 for bug 1435594

StacktraceTop:
 g_type_check_instance_cast (type_instance=type_instance@entry=0x26ce990, iface_type=40700368) at /build/buildd/glib2.0-2.42.1/./gobject/gtype.c:4014
 device_ethernet_refresh_ui (device=0x26ce990) at net-device-ethernet.c:213
 g_closure_invoke (closure=0x26fbdf0, return_value=0x0, n_param_values=1, param_values=0x7fff27d7f3f0, invocation_hint=0x7fff27d7f390) at /build/buildd/glib2.0-2.42.1/./gobject/gclosure.c:768
 signal_emit_unlocked_R (node=node@entry=0x26c9470, detail=detail@entry=0, instance=instance@entry=0x26476f0, emission_return=emission_return@entry=0x0, instance_and_params=instance_and_params@entry=0x7fff27d7f3f0) at /build/buildd/glib2.0-2.42.1/./gobject/gsignal.c:3553
 g_signal_emit_valist (instance=<optimized out>, signal_id=<optimized out>, detail=<optimized out>, var_args=var_args@entry=0x7fff27d7f570) at /build/buildd/glib2.0-2.42.1/./gobject/gsignal.c:3309