Description of problem:
I think this was when trying to isolate the multi-user.target systemd unit.

Version-Release number of selected component:
cockpit-daemon-0.41-1.fc22

Additional info:
reporter:       libreport-2.4.0
backtrace_rating: 4
cmdline:        /usr/libexec/cockpitd
crash_function: g_assertion_message_error
executable:     /usr/libexec/cockpitd
kernel:         4.0.0-0.rc2.git0.1.fc22.x86_64
runlevel:       5 3
type:           CCpp
uid:            1000

Truncated backtrace:
Thread no. 1 (10 frames)
 #3 g_assertion_message_error at gtestutils.c:2460
 #4 g_dbus_object_manager_server_emit_interfaces_removed at gdbusobjectmanagerserver.c:963
 #5 g_dbus_object_manager_server_unexport_unlocked at gdbusobjectmanagerserver.c:657
 #6 g_dbus_object_manager_server_unexport at gdbusobjectmanagerserver.c:689
 #7 provider_update_objects at src/daemon/storageprovider.c:338
 #8 provider_update at src/daemon/storageprovider.c:472
 #12 g_signal_emit_by_name at gsignal.c:3401
 #13 on_notify_g_name_owner at gdbusobjectmanagerclient.c:1268
 #19 g_object_notify_by_spec_internal at gobject.c:1149
 #20 g_object_notify at gobject.c:1197