(gnome-calendar:16194): GLib-CRITICAL **: g_date_time_get_day_of_month: assertion 'datetime != NULL' failed

(gnome-calendar:16194): GLib-CRITICAL **: g_date_time_difference: assertion 'begin != NULL' failed

(gnome-calendar:16194): GLib-CRITICAL **: g_date_time_get_day_of_month: assertion 'datetime != NULL' failed

(gnome-calendar:16194): GLib-CRITICAL **: g_date_time_unref: assertion 'datetime->ref_count > 0' failed

(gnome-calendar:16194): GLib-CRITICAL **: g_date_time_difference: assertion 'begin != NULL' failed

(gnome-calendar:16194): GLib-CRITICAL **: g_date_time_get_day_of_month: assertion 'datetime != NULL' failed

(gnome-calendar:16194): GLib-CRITICAL **: g_date_time_difference: assertion 'begin != NULL' failed

(gnome-calendar:16194): GLib-CRITICAL **: g_date_time_get_day_of_month: assertion 'datetime != NULL' failed

Thread 1 "gnome-calendar" received signal SIGSEGV, Segmentation fault.
g_time_zone_unref (tz=0xaeb560) at /usr/src/debug/dev-libs/glib-2.48.0/glib-2.48.0/glib/gtimezone.c:234
234	          for (idx = 0; idx < tz->t_info->len; idx++)
(gdb) bt
#0  g_time_zone_unref (tz=0xaeb560) at /usr/src/debug/dev-libs/glib-2.48.0/glib-2.48.0/glib/gtimezone.c:234
#1  0x00007ffff6acf075 in g_date_time_unref (datetime=0x688600) at /usr/src/debug/dev-libs/glib-2.48.0/glib-2.48.0/glib/gdatetime.c:475
#2  0x0000000000438a61 in show_new_event_widget (view=<optimized out>, start_span=0x6bd920, end_span=0x6c1ee0, x=662,5, y=688,33333333333337, window=0x6180b0) at gcal-window.c:710
#3  0x00007ffff1f7ed00 in ffi_call_unix64 () from /usr/lib64/libffi.so.6
#4  0x00007ffff1f7e604 in ffi_call () from /usr/lib64/libffi.so.6
#5  0x00007ffff6bbe609 in g_cclosure_marshal_generic (closure=0x9b5bc0, return_gvalue=0x0, n_param_values=<optimized out>, param_values=0x7fffffffd540, invocation_hint=<optimized out>, marshal_data=0x0)
    at /usr/src/debug/dev-libs/glib-2.48.0/glib-2.48.0/gobject/gclosure.c:1490
#6  0x00007ffff6bbdde5 in g_closure_invoke (closure=0x9b5bc0, return_value=return_value@entry=0x0, n_param_values=5, param_values=param_values@entry=0x7fffffffd540, invocation_hint=invocation_hint@entry=0x7fffffffd4c0)
    at /usr/src/debug/dev-libs/glib-2.48.0/glib-2.48.0/gobject/gclosure.c:804
#7  0x00007ffff6bd08e1 in signal_emit_unlocked_R (node=node@entry=0x61bdb0, detail=detail@entry=0, instance=instance@entry=0x50a510, emission_return=emission_return@entry=0x0, instance_and_params=instance_and_params@entry=0x7fffffffd540)
    at /usr/src/debug/dev-libs/glib-2.48.0/glib-2.48.0/gobject/gsignal.c:3629
#8  0x00007ffff6bd995c in g_signal_emit_valist (instance=instance@entry=0x50a510, signal_id=signal_id@entry=352, detail=detail@entry=0, var_args=var_args@entry=0x7fffffffd7a8)
    at /usr/src/debug/dev-libs/glib-2.48.0/glib-2.48.0/gobject/gsignal.c:3385
#9  0x00007ffff6bda175 in g_signal_emit_by_name (instance=0x50a510, detailed_signal=detailed_signal@entry=0x440046 "create-event") at /usr/src/debug/dev-libs/glib-2.48.0/glib-2.48.0/gobject/gsignal.c:3481
#10 0x000000000042746c in show_popover_for_position (view=<optimized out>, x=x@entry=662,5, y=y@entry=688,33333333333337, on_indicator=<optimized out>) at gcal-month-view.c:303
#11 0x000000000042831d in gcal_month_view_button_release (widget=0x50a510, event=0x1894e50) at gcal-month-view.c:1966
#12 0x00007ffff72d1e9a in _gtk_marshal_BOOLEAN__BOXEDv (closure=0x5366b0, return_value=0x7fffffffdba0, instance=<optimized out>, args=<optimized out>, marshal_data=<optimized out>, n_params=<optimized out>, param_types=0x532d60)
    at /usr/src/debug/x11-libs/gtk+-3.20.2/gtk+-3.20.2/gtk/gtkmarshalers.c:131
#13 0x00007ffff6bbe014 in _g_closure_invoke_va (closure=closure@entry=0x5366b0, return_value=return_value@entry=0x7fffffffdba0, instance=instance@entry=0x50a510, args=args@entry=0x7fffffffdc70, n_params=<optimized out>, 
    param_types=0x532d60) at /usr/src/debug/dev-libs/glib-2.48.0/glib-2.48.0/gobject/gclosure.c:867
#14 0x00007ffff6bd90b8 in g_signal_emit_valist (instance=0x50a510, signal_id=<optimized out>, detail=0, var_args=var_args@entry=0x7fffffffdc70) at /usr/src/debug/dev-libs/glib-2.48.0/glib-2.48.0/gobject/gsignal.c:3294
#15 0x00007ffff6bd9c97 in g_signal_emit (instance=instance@entry=0x50a510, signal_id=<optimized out>, detail=detail@entry=0) at /usr/src/debug/dev-libs/glib-2.48.0/glib-2.48.0/gobject/gsignal.c:3441
#16 0x00007ffff742f78c in gtk_widget_event_internal (widget=0x50a510, event=0x1894e50) at /usr/src/debug/x11-libs/gtk+-3.20.2/gtk+-3.20.2/gtk/gtkwidget.c:7704
#17 0x00007ffff72ceeee in propagate_event_up (topmost=<optimized out>, event=<optimized out>, widget=0x50a510) at /usr/src/debug/x11-libs/gtk+-3.20.2/gtk+-3.20.2/gtk/gtkmain.c:2542
#18 propagate_event (widget=<optimized out>, event=0x1894e50, captured=<optimized out>, topmost=0x0) at /usr/src/debug/x11-libs/gtk+-3.20.2/gtk+-3.20.2/gtk/gtkmain.c:2644
#19 0x00007ffff72d0e68 in gtk_main_do_event (event=0x1894e50) at /usr/src/debug/x11-libs/gtk+-3.20.2/gtk+-3.20.2/gtk/gtkmain.c:1875
#20 0x00007ffff6fda345 in _gdk_event_emit (event=event@entry=0x1894e50) at /usr/src/debug/x11-libs/gtk+-3.20.2/gtk+-3.20.2/gdk/gdkevents.c:73
#21 0x00007ffff702beb2 in gdk_event_source_dispatch (base=<optimized out>, callback=<optimized out>, data=<optimized out>) at /usr/src/debug/x11-libs/gtk+-3.20.2/gtk+-3.20.2/gdk/wayland/gdkeventsource.c:90
#22 0x00007ffff6ae7187 in g_main_dispatch (context=0x47c870) at /usr/src/debug/dev-libs/glib-2.48.0/glib-2.48.0/glib/gmain.c:3154
#23 g_main_context_dispatch (context=context@entry=0x47c870) at /usr/src/debug/dev-libs/glib-2.48.0/glib-2.48.0/glib/gmain.c:3769
#24 0x00007ffff6ae73e0 in g_main_context_iterate (context=context@entry=0x47c870, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at /usr/src/debug/dev-libs/glib-2.48.0/glib-2.48.0/glib/gmain.c:3840
#25 0x00007ffff6ae748c in g_main_context_iteration (context=context@entry=0x47c870, may_block=may_block@entry=1) at /usr/src/debug/dev-libs/glib-2.48.0/glib-2.48.0/glib/gmain.c:3901
#26 0x00007ffff6cb8e6d in g_application_run (application=0x4820e0, argc=argc@entry=1, argv=argv@entry=0x7fffffffe0f8) at /usr/src/debug/dev-libs/glib-2.48.0/glib-2.48.0/gio/gapplication.c:2381
#27 0x00000000004162f6 in main (argc=1, argv=0x7fffffffe0f8) at main.c:43
(gdb) 

