Comment 2 for bug 1208583

StacktraceTop:
 g_type_check_instance_cast (type_instance=type_instance@entry=0x7ff204ceab70, iface_type=140677416015024) at /build/buildd/glib2.0-2.37.3/./gobject/gtype.c:4008
 adjustment_changed_cb (adjustment=0x7ff2036908d0, user_data=0x7ff204ceab70) at ../../../os/os-scrollbar.c:1349
 g_closure_invoke (closure=0x7ff205040ef0, return_value=0x0, n_param_values=1, param_values=0x7fff02ce1350, invocation_hint=0x7fff02ce12f0) at /build/buildd/glib2.0-2.37.3/./gobject/gclosure.c:777
 signal_emit_unlocked_R (node=node@entry=0x7ff204ce3e30, detail=detail@entry=0, instance=instance@entry=0x7ff2036908d0, emission_return=emission_return@entry=0x0, instance_and_params=instance_and_params@entry=0x7fff02ce1350) at /build/buildd/glib2.0-2.37.3/./gobject/gsignal.c:3582
 g_signal_emit_valist (instance=<optimized out>, signal_id=<optimized out>, detail=<optimized out>, var_args=var_args@entry=0x7fff02ce14d8) at /build/buildd/glib2.0-2.37.3/./gobject/gsignal.c:3326