Sans le mode verbose, rien.
Cependant avec le mode verbose j’obtiens ceci :
alexandre@debian:~$ gnome-control-center --verbose
(gnome-control-center:10635): DEBUG: 11:37:06.101: Enabling debugging
(gnome-control-center:10635): AccountsService-DEBUG: 11:37:06.175: ActUserManager: calling 'ListCachedUsers'
(gnome-control-center:10635): AccountsService-DEBUG: 11:37:06.175: Failed to identify the current session: No data available
(gnome-control-center:10635): AccountsService-DEBUG: 11:37:06.175: ActUserManager: seat unloaded, so trying to set loaded property
(gnome-control-center:10635): AccountsService-DEBUG: 11:37:06.175: ActUserManager: Listing cached users, so not setting loaded property
(gnome-control-center:10635): AccountsService-DEBUG: 11:37:06.175: ActUserManager: Listing cached users, so not setting loaded property
(gnome-control-center:10635): AccountsService-DEBUG: 11:37:06.176: ActUserManager: ListCachedUsers finished, will set loaded property after list is fully loaded
(gnome-control-center:10635): AccountsService-DEBUG: 11:37:06.176: ActUserManager: tracking new user with object path /org/freedesktop/Accounts/User1000
(gnome-control-center:10635): AccountsService-DEBUG: 11:37:06.180: ActUserManager: unrefing manager owned by finished ListCachedUsers call
(gnome-control-center:10635): AccountsService-DEBUG: 11:37:06.181: ActUserManager: user alexandre is now loaded
(gnome-control-center:10635): AccountsService-DEBUG: 11:37:06.181: ActUserManager: user alexandre was not yet known, adding it
(gnome-control-center:10635): AccountsService-DEBUG: 11:37:06.181: ActUserManager: tracking user 'alexandre'
(gnome-control-center:10635): AccountsService-DEBUG: 11:37:06.181: ActUserManager: not yet loaded, so not emitting user-added signal
(gnome-control-center:10635): AccountsService-DEBUG: 11:37:06.181: ActUserManager: no pending users, trying to set loaded property
(gnome-control-center:10635): AccountsService-DEBUG: 11:37:06.181: ActUserManager: Seat wouldn't load, so giving up on it and setting loaded property
(gnome-control-center:10635): AccountsService-DEBUG: 11:37:06.181: ActUserManager: user manager now loaded, proceeding with fetch user request for user with id 1000
(gnome-control-center:10635): AccountsService-DEBUG: 11:37:06.181: ActUserManager: finding user with id 1000 state 2
(gnome-control-center:10635): AccountsService-DEBUG: 11:37:06.181: ActUserManager: Looking for user with id 1000 in accounts service
(gnome-control-center:10635): AccountsService-DEBUG: 11:37:06.182: ActUserManager: sending user-changed signal for user alexandre
(gnome-control-center:10635): AccountsService-DEBUG: 11:37:06.182: ActUserManager: sent user-changed signal for user alexandre
(gnome-control-center:10635): AccountsService-DEBUG: 11:37:06.182: ActUserManager: updating user alexandre
(gnome-control-center:10635): AccountsService-DEBUG: 11:37:06.182: ActUserManager: Found object path of user with id 1000: /org/freedesktop/Accounts/User1000
(gnome-control-center:10635): AccountsService-DEBUG: 11:37:06.182: ActUserManager: finding user with id 1000 state 3
(gnome-control-center:10635): AccountsService-DEBUG: 11:37:06.182: ActUserManager: user with id 1000 fetched
(gnome-control-center:10635): AccountsService-DEBUG: 11:37:06.185: ActUserManager: finished handling request for user with id 1000
(gnome-control-center:10635): AccountsService-DEBUG: 11:37:06.185: ActUserManager: unrefing manager owned by fetch user request
(gnome-control-center:10635): AccountsService-DEBUG: 11:37:06.199: ActUserManager: user alexandre is now loaded
(gnome-control-center:10635): AccountsService-DEBUG: 11:37:06.199: ActUserManager: sessions changed (user alexandre) num=0
(gnome-control-center:10635): AccountsService-DEBUG: 11:37:06.199: ActUserManager: no pending users, trying to set loaded property
(gnome-control-center:10635): AccountsService-DEBUG: 11:37:06.199: ActUserManager: already loaded, so not setting loaded property
alexandre@debian:~$