(gdb) bt
#0  0x000000021038ad5a in g_time_zone_new (identifier=0x0) at gtimezone.c:392
#1  0x000000021034c8f3 in g_date_time_new_now_local () at gdatetime.c:728
#2  0x000000020ff0ea50 in update_clock (data=Variable "data" is not available.
) at gnome-wall-clock.c:176
#3  0x000000020ff0fa42 in g_datetime_source_dispatch (source=Variable "source" is not available.
) at gnome-datetime-source.c:142
#4  0x00000002103601d5 in g_main_context_dispatch (context=0x204648e00) at gmain.c:2441
#5  0x0000000210363a3c in g_main_context_iterate (context=0x204648e00, block=1, dispatch=1, self=Variable "self" is not available.
) at gmain.c:3089
#6  0x0000000210363f5e in g_main_context_iteration (context=0x204648e00, may_block=1) at gmain.c:3152
#7  0x0000000202da3e55 in gtk_main_iteration () from /usr/local/lib/libgtk-3.so.1.0
#8  0x000000000040e159 in gs_manager_set_active ()
#9  0x000000000040a198 in gs_monitor_new ()
#10 0x0000000000417512 in gs_marshal_BOOLEAN__BOOLEAN ()
#11 0x000000020cbb0399 in g_closure_invoke (closure=0x207bb6b00, return_value=0x7f7ffffeb080, n_param_values=2, param_values=0x20bf4f090, 
    invocation_hint=0x7f7ffffeaee0) at gclosure.c:774
#12 0x000000020cbc6ba4 in signal_emit_unlocked_R (node=0x200f1f700, detail=0, instance=0x20f446ec0, emission_return=0x7f7ffffeb080, 
    instance_and_params=0x20bf4f090) at gsignal.c:3272
#13 0x000000020cbc860b in g_signal_emit_valist (instance=0x20f446ec0, signal_id=Variable "signal_id" is not available.
) at gsignal.c:3013
#14 0x000000020cbc8d03 in g_signal_emit (instance=Variable "instance" is not available.
) at gsignal.c:3060
#15 0x000000000040bccf in gs_listener_set_active ()
#16 0x000000000040a2b8 in gs_monitor_new ()
#17 0x000000020cbb0399 in g_closure_invoke (closure=0x20465c040, return_value=0x0, n_param_values=1, param_values=0x20194ddc0, invocation_hint=0x7f7ffffeb4a0)
    at gclosure.c:774
#18 0x000000020cbc6ba4 in signal_emit_unlocked_R (node=0x200f1f680, detail=0, instance=0x20f446ec0, emission_return=0x0, instance_and_params=0x20194ddc0)
    at gsignal.c:3272
#19 0x000000020cbc894b in g_signal_emit_valist (instance=0x20f446ec0, signal_id=Variable "signal_id" is not available.
) at gsignal.c:3003
#20 0x000000020cbc8d03 in g_signal_emit (instance=Variable "instance" is not available.
) at gsignal.c:3060
#21 0x000000000040c226 in gs_listener_set_active ()
#22 0x000000021129cabf in dbus_connection_dispatch () from /usr/local/lib/libdbus-1.so.9.1
#23 0x0000000212b86325 in dbus_server_setup_with_g_main () from /usr/local/lib/libdbus-glib-1.so.4.3
#24 0x00000002103601d5 in g_main_context_dispatch (context=0x204648e00) at gmain.c:2441
#25 0x0000000210363a3c in g_main_context_iterate (context=0x204648e00, block=1, dispatch=1, self=Variable "self" is not available.
) at gmain.c:3089
#26 0x0000000210363d5a in g_main_loop_run (loop=0x20465e670) at gmain.c:3297
#27 0x0000000202da3f5d in gtk_main () from /usr/local/lib/libgtk-3.so.1.0
#28 0x0000000000409aaf in main ()
(gdb) bt full
#0  0x000000021038ad5a in g_time_zone_new (identifier=0x0) at gtimezone.c:392
        header = (const struct tzhead *) 0x202443000
        tz = (GTimeZone *) 0x205d52280
#1  0x000000021034c8f3 in g_date_time_new_now_local () at gdatetime.c:728
        datetime = Variable "datetime" is not available.

