I noticed that the process gnome-shell-calendar-server puts up a password prompt which eats 100% CPU as long as it hasn't been closed.

I made a backtrace:


#0  0x00007ff06fddc39c in __libc_recv (fd=<optimized out>, buf=<optimized out>, n=<optimized out>, 
    flags=<optimized out>) at ../sysdeps/unix/sysv/linux/x86_64/recv.c:34
#1  0x00007ff068bfb04f in ?? () from /usr/lib64/libxcb.so.1
#2  0x00007ff068bfb576 in ?? () from /usr/lib64/libxcb.so.1
#3  0x00007ff06dd827c9 in ?? () from /usr/lib64/libX11.so.6
#4  0x00007ff06dd82891 in ?? () from /usr/lib64/libX11.so.6
#5  0x00007ff06dd82fbd in _XEventsQueued () from /usr/lib64/libX11.so.6
#6  0x00007ff06dd7468d in XPending () from /usr/lib64/libX11.so.6
#7  0x00007ff06f29ea7b in gdk_check_xpending (display=0x724010 [GdkX11Display]) at gdkeventsource.c:266
#8  gdk_event_source_prepare (source=<optimized out>, timeout=<optimized out>) at gdkeventsource.c:280
#9  0x00007ff07003143e in g_main_context_prepare (context=0x733980, priority=0x7fff153de848)
    at gmain.c:2813
#10 0x00007ff070031c3b in g_main_context_iterate (dispatch=1, block=1, context=0x733980, 
    self=<optimized out>) at gmain.c:3103
#11 g_main_context_iterate (context=0x733980, block=1, dispatch=1, self=<optimized out>) at gmain.c:3060
#12 0x00007ff070031e44 in g_main_context_iteration (context=0x733980, may_block=1) at gmain.c:3184
#13 0x00007ff07139e5e4 in ep_msg_send (msg=0x95e350) at e-passwords.c:386
#14 0x00007ff0713a0223 in e_passwords_ask_password (title=0x7ff071b33713 "Wachtwoord invoeren", 
    unused=<optimized out>, key=
    0x930b40 "caldav://reinout%40gmail.com@www.google.com/calendar/dav/pe07e4o648n6r24fi4pqh2fp4k@group.calendar.google.com/events", prompt=
    0x94e650 "Wachtwoord invoeren voor agenda <b>GL Campagne</b> (gebruiker <b>reinout@gmail.com</b>)", 
    remember_type=1282, remember=0x7fff153de9bc, parent=0x0) at e-passwords.c:1115
#15 0x00007ff07138ead0 in e_credentials_authenticate_helper (credentials=0x939720, parent=0x0, 
    remember_password=0x7fff153de9bc) at e-client-utils.c:994
#16 0x00007ff07138edec in e_client_utils_authenticate_handler (client=<optimized out>, credentials=
    0x939720, gtk_window_parent=0x0) at e-client-utils.c:897
#17 0x00007ff070abadb8 in e_gdbus_marshallers_BOOLEAN__POINTER (closure=0x86eb70, return_value=
    0x7fff153dedd0, n_param_values=<optimized out>, param_values=0x7fff153dec00, 
    invocation_hint=<optimized out>, marshal_data=<optimized out>) at e-gdbus-marshallers.c:85
#18 0x00007ff0702edca2 in g_closure_invoke (closure=0x86eb70, return_value=0x7fff153dedd0, 
    n_param_values=2, param_values=0x7fff153dec00, invocation_hint=<optimized out>) at gclosure.c:777
#19 0x00007ff0702fed71 in signal_emit_unlocked_R (node=<optimized out>, detail=0, 
    instance=<optimized out>, emission_return=0x7fff153dedd0, instance_and_params=0x7fff153dec00)
    at gsignal.c:3547
#20 0x00007ff070306d7e in g_signal_emit_valist (instance=0x731480, signal_id=<optimized out>, detail=0, 
    var_args=<optimized out>) at gsignal.c:3306
#21 0x00007ff070307242 in g_signal_emit (instance=<optimized out>, signal_id=<optimized out>, 
    detail=<optimized out>) at gsignal.c:3352
#22 0x00007ff070ac115f in e_client_emit_authenticate (client=0x731480 [ECalClient], credentials=0x939720)
    at e-client.c:957
#23 0x00007ff070ac46b6 in client_process_authentication_idle_cb (user_data=0x939700) at e-client.c:895
#24 client_process_authentication_idle_cb (user_data=0x939700) at e-client.c:881
#25 0x00007ff0700319ba in g_main_dispatch (context=0x733980) at gmain.c:2515
#26 g_main_context_dispatch (context=0x733980) at gmain.c:3052
#27 0x00007ff070031d80 in g_main_context_iterate (dispatch=1, block=<optimized out>, context=0x733980, 
    self=<optimized out>) at gmain.c:3123
#28 g_main_context_iterate (context=0x733980, block=<optimized out>, dispatch=1, self=<optimized out>)
    at gmain.c:3060
#29 0x00007ff070031e44 in g_main_context_iteration (context=0x733980, may_block=0) at gmain.c:3184
#30 0x00007ff070acc633 in e_gdbus_proxy_call_sync (proxy=<optimized out>, cancellable=
    0x93d430 [GCancellable], error=0x7fff153df128, start_func=0x7ff0718602c0, 
    finish_func=<optimized out>, in_type=<optimized out>, in_value=0x7fff153df0fc, out_type=2, out_value=
    0x0) at e-gdbus-templates.c:1486
#31 0x00007ff070acfac8 in e_gdbus_proxy_call_sync_boolean__void (proxy=<optimized out>, in_boolean=1, 
    cancellable=<optimized out>, error=<optimized out>, start_func=<optimized out>, 
    finish_func=<optimized out>) at e-gdbus-templates.c:1587
#32 0x00007ff070ac7518 in e_client_proxy_call_sync_boolean__void (client=0x7315a0 [ECalClient], 
    in_boolean=1, cancellable=<optimized out>, error=0x7fff153df230, func=
    0x7ff071862130 <e_gdbus_cal_call_open_sync>) at e-client.c:2890
#33 0x0000000000404f3c in app_load_events (app=0x83b990)
    at calendar-server/gnome-shell-calendar-server.c:631
#34 0x00000000004057fb in handle_method_call (connection=<optimized out>, sender=<optimized out>, 
    object_path=<optimized out>, interface_name=<optimized out>, method_name=<optimized out>, 
    parameters=<optimized out>, invocation=0x7ff058004300 [GDBusMethodInvocation], user_data=0x83b990)
    at calendar-server/gnome-shell-calendar-server.c:850
#35 0x00007ff0705e60eb in call_in_idle_cb (user_data=<optimized out>) at gdbusconnection.c:4687
#36 0x00007ff0700319ba in g_main_dispatch (context=0x733980) at gmain.c:2515
#37 g_main_context_dispatch (context=0x733980) at gmain.c:3052
#38 0x00007ff070031d80 in g_main_context_iterate (dispatch=1, block=<optimized out>, context=0x733980, 
    self=<optimized out>) at gmain.c:3123
#39 g_main_context_iterate (context=0x733980, block=<optimized out>, dispatch=1, self=<optimized out>)
    at gmain.c:3060
#40 0x00007ff07003217a in g_main_loop_run (loop=0x83f1e0) at gmain.c:3317
#41 0x00007ff070e6cded in gtk_main () at gtkmain.c:1161
#42 0x000000000040396f in main (argc=1, argv=0x7fff153df758)
    at calendar-server/gnome-shell-calendar-server.c:1050