@Terry parece estar certo.
chamando unity
em um Ctrl-Alt-F1 tty com a seguinte saída e quebra a sessão de unidade em execução (Ctrl-Alt-F7):
Welcome to Ubuntu 11.04 (GNU/Linux 2.6.38-8-generic x86_64)
* Documentation: https://help.ubuntu.com/
user@host:~$ unity &
[1] 3137
user@host:~$ WARNING: no DISPLAY variable set, setting it to :0
unity-panel-service: no process found
(process:3139): GLib-WARNING **: In call to g_spawn_sync(), exit status of a child process was requested but SIGCHLD action was set to SIG_IGN and ECHILD was received by waitpid(), so exit status can't be returned. This is a bug in the program calling g_spawn_sync(); either don't request the exit status, or don't set the SIGCHLD action.
GConf Error: Failed to contact configuration server; the most common cause is a missing or misconfigured D-Bus session bus daemon. See http://projects.gnome.org/gconf/ for information. (Details - 1: Failed to get connection to session: Abnormal program termination spawning command line 'dbus-launch --autolaunch=e1415082f4c221cc22bbf8954b115eb2 --binary-syntax --close-stderr': )
Backend : gconf
Integration : true
Profile : unity
Adding plugins
Initializing core options...done
Window created on XQueryTree, map state isViewable? 0
...
... repeated 80 times
...
Window created on XQueryTree, map state isViewable? 1
Initializing bailer options...done
Initializing detection options...done
Initializing composite options...done
Initializing opengl options...done
Initializing decor options...done
Initializing vpswitch options...done
Initializing obs options...done
Initializing grid options...done
Initializing move options...done
Initializing commands options...done
Initializing gnomecompat options...done
Initializing place options...done
Initializing unitymtgrabhandles options...done
Initializing resize options...done
Initializing mousepoll options...done
Initializing animation options...done
Initializing wall options...done
Initializing session options...done
Initializing wobbly options...done
Initializing workarounds options...done
Initializing expo options...done
Initializing ezoom options...done
Initializing staticswitcher options...done
Initializing fade options...done
Initializing scale options...done
** (<unknown>:3139): DEBUG: Unity accessibility initialization
** (<unknown>:3139): DEBUG: Shows on edge: 1
(<unknown>:3139): GLib-GObject-WARNING **: invalid (NULL) pointer instance
(<unknown>:3139): GLib-GObject-CRITICAL **: g_signal_connect_data: assertion 'G_TYPE_CHECK_INSTANCE (instance)' failed
Screen geometry changed:
Monitor 0(primary)
0x0x1920x1200
unity-panel-service: no process found
** (<unknown>:3139): DEBUG: PanelController:: Added Panel for Monitor 0
Initializing unityshell options...done
** (<unknown>:3139): DEBUG: PlaceEntry: Applications
** (<unknown>:3139): DEBUG: PlaceEntry: Commands
** (<unknown>:3139): DEBUG: PlaceEntry: Files & Folders
** (<unknown>:3139): DEBUG: /com/canonical/unity/applicationsplace
** (<unknown>:3139): DEBUG: /com/canonical/unity/filesplace
Couldn't find a perfect decorator match; trying all decorators
Starting unity-window-decorator
** (<unknown>:3139): DEBUG: Setting to primary screen rect: x=0 y=0 w=1920 h=1200
** (<unknown>:3139): DEBUG: Lost the name com.canonical.Unity.Launcher on the session bus
** (<unknown>:3139): DEBUG: IndicatorAdded: libapplication.so
** (<unknown>:3139): DEBUG: IndicatorAdded: libsoundmenu.so
** (<unknown>:3139): DEBUG: IndicatorAdded: libmessaging.so
** (<unknown>:3139): DEBUG: IndicatorAdded: libdatetime.so
** (<unknown>:3139): DEBUG: IndicatorAdded: libme.so
** (<unknown>:3139): DEBUG: IndicatorAdded: libsession.so
Segmentation fault