Ok, second try generated a valid report crash, apport-retrace also made (I hope) a usefull stacktrace :
--- stack trace --- #0 0x0805ffbc in xsession_start (session=0x8e4e060) at xsession.c:80 path = <optimized out> error = 0x0 #1 0x0805943f in session_start (session=0x8e4e060) at session.c:226 user = <optimized out> orig_path = <optimized out> result = <optimized out> __PRETTY_FUNCTION__ = "session_start" #2 0x0804e962 in start_user_session (display=0x8e28c10, authentication=0x8e45538) at display.c:799 user = <optimized out> log_filename = 0x8e44560 "sbin:/bin:/usr/games" result = 0 #3 0x080501f6 in greeter_session_stopped_cb (display=0x8e28c10, session=<optimized out>) at display.c:507 started_session = <optimized out> #4 greeter_session_stopped_cb (session=0x8e4e010, display=0x8e28c10) at display.c:483 No locals. #5 0x00c70f6c in g_cclosure_marshal_VOID__VOID (closure=0x8e398d0, return_value=0x0, n_param_values=1, param_values=0x8e4d850, invocation_hint=0xbfe024b0, marshal_data=0x0) at /build/buildd/glib2.0-2.29.16/./gobject/gmarshal.c:85 callback = 0x80500b0 <greeter_session_stopped_cb> cc = 0x8e398d0 data1 = 0x8e4e010 data2 = <optimized out> __PRETTY_FUNCTION__ = "g_cclosure_marshal_VOID__VOID" #6 0x00c6fa5c in g_closure_invoke (closure=0x8e398d0, return_value=0x0, n_param_values=1, param_values=0x8e4d850, invocation_hint=0xbfe024b0) at /build/buildd/glib2.0-2.29.16/./gobject/gclosure.c:773 marshal = 0x804b5f0 <g_cclosure_marshal_VOID__VOID@plt> marshal_data = 0x0 in_marshal = 0 __PRETTY_FUNCTION__ = "g_closure_invoke" #7 0x00c83ec0 in signal_emit_unlocked_R (node=0x8e19ff0, detail=0, instance=0x8e4e010, emission_return=0x0, instance_and_params=0x8e4d850) at /build/buildd/glib2.0-2.29.16/./gobject/gsignal.c:3271 tmp = <optimized out> handler = 0x8e1e120 accumulator = 0x0 emission = {next = 0x0, instance = 0x8e4e010, ihint = {signal_id = 7, detail = 0, run_type = G_SIGNAL_RUN_FIRST}, state = EMISSION_RUN, chain_type = 4} class_closure = 0x8e19fc8 hlist = 0x8e43e78 handler_list = 0x8e1e120 return_accu = 0x0 accu = {g_type = 0, data = {{v_int = 0, v_uint = 0, v_long = 0, v_ulong = 0, v_int64 = 0, v_uint64 = 0, v_float = 0, v_double = 0, v_pointer = 0x0}, {v_int = 0, v_uint = 0, v_long = 0, v_ulong = 0, v_int64 = 0, v_uint64 = 0, v_float = 0, v_double = 0, v_pointer = 0x0}}} signal_id = 7 max_sequential_handler_number = 30 return_value_altered = 0 #8 0x00c8cb8f in g_signal_emit_valist (instance=0x8e4e010, signal_id=7, detail=0, var_args=0xbfe0265c "\364?\377") at /build/buildd/glib2.0-2.29.16/./gobject/gsignal.c:3002 instance_and_params = 0x8e4d850 signal_return_type = 4 param_values = 0x8e4d864 node = 0x8e19ff0 i = <optimized out> n_params = 0 __PRETTY_FUNCTION__ = "g_signal_emit_valist" #9 0x00c8cd03 in g_signal_emit (instance=0x8e4e010, signal_id=7, detail=0) at /build/buildd/glib2.0-2.29.16/./gobject/gsignal.c:3059 var_args = 0xbfe0265c "\364?\377" #10 0x00f3a742 in g_child_watch_dispatch (source=0x8e4e8b8, callback=0x8055ad0 <process_watch_cb>, user_data=0x8e4e010) at /build/buildd/glib2.0-2.29.16/./glib/gmain.c:4447 child_watch_source = 0x8e4e8b8 child_watch_callback = 0x8055ad0 <process_watch_cb> #11 0x00f3e81f in g_main_dispatch (context=0x8e1a170) at /build/buildd/glib2.0-2.29.16/./glib/gmain.c:2439 dispatch = 0xf3a710 <g_child_watch_dispatch> was_in_call = 0 user_data = 0x8e4e010 callback = 0x8055ad0 <process_watch_cb> cb_funcs = 0xff435c cb_data = 0x8e4f368 current_source_link = {data = 0x8e4e8b8, next = 0x0} need_destroy = <optimized out> source = 0x8e4e8b8 current = 0x8e304c8 i = <optimized out> #12 g_main_context_dispatch (context=0x8e1a170) at /build/buildd/glib2.0-2.29.16/./glib/gmain.c:3008 No locals. #13 0x00f3ef50 in g_main_context_iterate (context=0x8e1a170, block=16046352, dispatch=1, self=<optimized out>) at /build/buildd/glib2.0-2.29.16/./glib/gmain.c:3086 max_priority = 0 timeout = 0 some_ready = 1 nfds = <optimized out> allocated_nfds = <optimized out> fds = 0x8e4eac8 #14 0x00f3f55b in g_main_loop_run (loop=0x8e1f130) at /build/buildd/glib2.0-2.29.16/./glib/gmain.c:3294 __PRETTY_FUNCTION__ = "g_main_loop_run" #15 0x0804cf0b in main (argc=1, argv=0xbfe02aa4) at lightdm.c:1117 pid_file = <optimized out> option_context = <optimized out> groups = 0x8e22a28 i = <optimized out> n_seats = <optimized out> explicit_config = 0 test_mode = 0 pid_path = 0x8061587 "/var/run/lightdm.pid" xserver_command = 0x0 passwd_path = 0x0 xsessions_dir = 0x0 xgreeters_dir = 0x0 greeter_session = 0x0 user_session = 0x0 session_wrapper = 0x0 config_dir = <optimized out> log_dir = 0x0 run_dir = 0x0 cache_dir = 0x0 default_log_dir = <optimized out> default_run_dir = 0x0 default_cache_dir = 0x8e22a28 "\001" minimum_vt = 0x0 minimum_display_number = 0x0 show_version = 0 options = {{long_name = 0x80632db "config", short_name = 99 'c', flags = 0, arg = G_OPTION_ARG_STRING, arg_data = 0x806b4a0, description = 0x80615d1 "Use configuration file", arg_description = 0x0}, {long_name = 0x80615e8 "debug", short_name = 100 'd', flags = 0, arg = G_OPTION_ARG_NONE, arg_data = 0x806b4a4, description = 0x80615ee "Print debugging messages", arg_description = 0x0}, {long_name = 0x8061607 "test-mode", short_name = 0 '\000', flags = 0, arg = G_OPTION_ARG_NONE, arg_data = 0xbfe029ac, description = 0x80621c8 "Run as unprivileged user, skipping things that require root access", arg_description = 0x0}, {long_name = 0x8061611 "passwd-file", short_name = 0 '\000', flags = 0, arg = G_OPTION_ARG_STRING, arg_data = 0xbfe029b8, description = 0x806220c "Use the given password file for authentication (for testing, requires --no-root)", arg_description = 0x806161d "FILE"}, {long_name = 0x8061622 "pid-file", short_name = 0 '\000', flags = 0, arg = G_OPTION_ARG_STRING, arg_data = 0xbfe029b0, description = 0x806162b "File to write PID into", arg_description = 0x806161d "FILE"}, {long_name = 0x8061642 "xserver-command", short_name = 0 '\000', flags = 0, arg = G_OPTION_ARG_STRING, arg_data = 0xbfe029b4, description = 0x8061652 "Command to run X servers", arg_description = 0x806166b "COMMAND"}, {long_name = 0x8061673 "greeter-session", short_name = 0 '\000', flags = 0, arg = G_OPTION_ARG_STRING, arg_data = 0xbfe029c4, description = 0x8061683 "Greeter session", arg_description = 0x8060770 "SESSION"}, {long_name = 0x8061693 "user-session", short_name = 0 '\000', flags = 0, arg = G_OPTION_ARG_STRING, arg_data = 0xbfe029c8, description = 0x80616a0 "User session", arg_description = 0x8060770 "SESSION"}, {long_name = 0x80616ad "session-wrapper", short_name = 0 '\000', flags = 0, arg = G_OPTION_ARG_STRING, arg_data = 0xbfe029cc, description = 0x80616bd "Session wrapper", arg_description = 0x8060770 "SESSION"}, {long_name = 0x80616cd "minimum-vt", short_name = 0 '\000', flags = 0, arg = G_OPTION_ARG_STRING, arg_data = 0xbfe029dc, description = 0x8062260 "Minimum VT to use for X servers", arg_description = 0x80616d8 "NUMBER"}, {long_name = 0x80616df "minimum-display-number", short_name = 0 '\000', flags = 0, arg = G_OPTION_ARG_STRING, arg_data = 0xbfe029e0, description = 0x8062280 "Minimum display number to use for X servers", arg_description = 0x80616d8 "NUMBER"}, {long_name = 0x80616f6 "xsessions-dir", short_name = 0 '\000', flags = 0, arg = G_OPTION_ARG_STRING, arg_data = 0xbfe029bc, description = 0x80622ac "Directory to load X sessions from", arg_description = 0x8061704 "DIRECTORY"}, {long_name = 0x806170e "xgreeters-dir", short_name = 0 '\000', flags = 0, arg = G_OPTION_ARG_STRING, arg_data = 0xbfe029c0, description = 0x80622d0 "Directory to load X greeters from", arg_description = 0x8061704 "DIRECTORY"}, {long_name = 0x806171c "log-dir", short_name = 0 '\000', flags = 0, arg = G_OPTION_ARG_STRING, arg_data = 0xbfe029d0, description = 0x8061724 "Directory to write logs to", arg_description = 0x8061704 "DIRECTORY"}, {long_name = 0x806173f "run-dir", short_name = 0 '\000', flags = 0, arg = G_OPTION_ARG_STRING, arg_data = 0xbfe029d4, description = 0x80622f4 "Directory to store running state", arg_description = 0x8061704 "DIRECTORY"}, {long_name = 0x8061747 "cache-dir", short_name = 0 '\000', flags = 0, arg = G_OPTION_ARG_STRING, arg_data = 0xbfe029d8, description = 0x8062318 "Directory to cached information", arg_description = 0x8061704 "DIRECTORY"}, {long_name = 0x806175e "version", short_name = 118 'v', flags = 0, arg = G_OPTION_ARG_NONE, arg_data = 0xbfe029e4, description = 0x8061751 "Show release version", arg_description = 0x0}, {long_name = 0x0, short_name = 0 '\000', flags = 0, arg = G_OPTION_ARG_NONE, arg_data = 0x0, description = 0x0, arg_description = 0x0}} error = 0x0 -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to lightdm in Ubuntu. https://bugs.launchpad.net/bugs/834793 Title: Crash on login, after installing on Lubuntu Status in Light Display Manager: New Status in “lightdm” package in Ubuntu: New Bug description: To reproduce : Install Lubuntu with a daily ISO After the installation, login to Lubuntu session Install lightdm and use it by default Reboot Log in Lubuntu session You shoudl have a black screen with nothing else, and a report in /var/crash which apport refuse to report. ProblemType: Bug DistroRelease: Ubuntu 11.10 Package: lightdm 0.9.3-0ubuntu8 ProcVersionSignature: Ubuntu 3.0.0-9.14-generic 3.0.3 Uname: Linux 3.0.0-9-generic i686 Architecture: i386 Date: Fri Aug 26 16:57:42 2011 InstallationMedia: Lubuntu 11.10 "Oneiric Ocelot" - Alpha i386 (20110825) ProcEnviron: LANG=fr_FR.UTF-8 SHELL=/bin/bash SourcePackage: lightdm UpgradeStatus: No upgrade log present (probably fresh install) To manage notifications about this bug go to: https://bugs.launchpad.net/lightdm/+bug/834793/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp