Thread 1 (Thread 0x7f6199850800 (LWP 375)):
#0  0x00007f619741cfe5 in __GI_raise (sig=sig@entry=6) at ../nptl/sysdeps/unix/sysv/linux/raise.c:63
#1  0x00007f6197420188 in __GI_abort () at abort.c:90
#2  0x00007f6198492c86 in g_assertion_message (domain=domain@entry=0x7f6198a9f838 "GLib-GIO", 
    file=file@entry=0x7f6198ac8740 "../../gio/gdbusobjectmanagerserver.c", line=line@entry=969, 
    func=func@entry=0x7f6198ac8d20 <__PRETTY_FUNCTION__.13146> "g_dbus_object_manager_server_emit_interfaces_removed", message=<optimized out>) at ../../glib/gtestutils.c:2030
#3  0x00007f6198492f2f in g_assertion_message_error (domain=domain@entry=0x7f6198a9f838 "GLib-GIO", 
    file=file@entry=0x7f6198ac8740 "../../gio/gdbusobjectmanagerserver.c", line=line@entry=969, 
    func=func@entry=0x7f6198ac8d20 <__PRETTY_FUNCTION__.13146> "g_dbus_object_manager_server_emit_interfaces_rem---Type <return> to continue, or q <return> to quit---
oved", expr=expr@entry=0x7f6198ab37f1 "error", error=0x203ea80, error_domain=error_domain@entry=0, 
    error_code=error_code@entry=0) at ../../glib/gtestutils.c:2121
#4  0x00007f6198a893f5 in g_dbus_object_manager_server_emit_interfaces_removed (
    manager=manager@entry=0x203a5c0, interfaces=0x2053970, data=0x204c1a0, data=0x204c1a0)
    at ../../gio/gdbusobjectmanagerserver.c:969
#5  0x00007f6198a89a2e in g_dbus_object_manager_server_unexport_unlocked (manager=manager@entry=0x203a5c0, 
    object_path=object_path@entry=0x20430f0 "/org/gnome/DisplayManager/Displays/_0")
    at ../../gio/gdbusobjectmanagerserver.c:663
#6  0x00007f6198a8aa6c in g_dbus_object_manager_server_unexport (manager=0x203a5c0, 
    object_path=0x20430f0 "/org/gnome/DisplayManager/Displays/_0") at ../../gio/gdbusobjectmanagerserver.c:695
#7  0x00007f6198460c1b in g_hash_table_find (hash_table=0x7f6190004120, 
    predicate=predicate@entry=0x409200 <find_func>, user_data=user_data@entry=0x7fffdf115970)
    at ../../glib/ghash.c:1587
#8  0x00000000004095bb in gdm_display_store_foreach (store=<optimized out>, 
    func=func@entry=0x40e720 <unexport_display>, user_data=user_data@entry=0x2042910)
    at ../../daemon/gdm-display-store.c:167
#9  0x000000000040f2a3 in gdm_manager_finalize (object=0x2042910) at ../../daemon/gdm-manager.c:1165
#10 0x00007f6198764258 in g_object_unref (_object=0x2042910) at ../../gobject/gobject.c:3189
#11 0x0000000000407c65 in bus_connection_closed () at ../../daemon/main.c:81
#12 0x00007f61969a9c7c in ffi_call_unix64 () at ../src/x86/unix64.S:75
#13 0x00007f61969a970a in ffi_call (cif=cif@entry=0x7fffdf115be0, 
    fn=fn@entry=0x407c20 <bus_connection_closed>, rvalue=0x7fffdf115b40, avalue=avalue@entry=0x7fffdf115ae0)
    at ../src/x86/ffi64.c:486
#14 0x00007f619875fb28 in g_cclosure_marshal_generic (closure=0x20401c0, return_gvalue=0x0, 
    n_param_values=<optimized out>, param_values=<optimized out>, invocation_hint=<optimized out>, 
    marshal_data=0x407c20 <bus_connection_closed>) at ../../gobject/gclosure.c:1454
#15 0x00007f619875f1f0 in g_closure_invoke (closure=0x20401c0, return_value=0x0, n_param_values=3, 
    param_values=0x7fffdf115e20, invocation_hint=0x7fffdf115dc0) at ../../gobject/gclosure.c:777
#16 0x00007f6198771ed0 in signal_emit_unlocked_R (node=node@entry=0x202ce60, detail=detail@entry=0, 
    instance=instance@entry=0x202e030, emission_return=emission_return@entry=0x0, 
    instance_and_params=instance_and_params@entry=0x7fffdf115e20) at ../../gobject/gsignal.c:3584
#17 0x00007f619877a0c4 in g_signal_emit_valist (instance=0x202e030, signal_id=<optimized out>, detail=0, 
    var_args=var_args@entry=0x7fffdf116088) at ../../gobject/gsignal.c:3328
#18 0x00007f619877a362 in g_signal_emit (instance=<optimized out>, signal_id=<optimized out>, 
    detail=detail@entry=0) at ../../gobject/gsignal.c:3384
#19 0x00007f6198a666e2 in emit_closed_in_idle (user_data=0x7f6190005910) at ../../gio/gdbusconnection.c:1377
---Type <return> to continue, or q <return> to quit---
#20 0x00007f6198470a15 in g_main_dispatch (context=0x202dbd0) at ../../glib/gmain.c:3058
#21 g_main_context_dispatch (context=context@entry=0x202dbd0) at ../../glib/gmain.c:3634
#22 0x00007f6198470d58 in g_main_context_iterate (context=0x202dbd0, block=block@entry=1, 
    dispatch=dispatch@entry=1, self=<optimized out>) at ../../glib/gmain.c:3705
#23 0x00007f61984711ca in g_main_loop_run (loop=0x2040d60) at ../../glib/gmain.c:3899
#24 0x00000000004078ca in main (argc=1, argv=0x7fffdf1163c8) at ../../daemon/main.c:421
(gdb) 
