I could fix this crash loally with "sudo chown -R lightdm.lightdm /var/lib/lightdm/" (on quantal).
The problem was: #0 g_logv (log_domain=0x0, log_level=G_LOG_LEVEL_ERROR, format=<optimized out>, args=args@entry=0x7fff6b957f48) at /build/buildd/glib2.0-2.34.0/./glib/gmessages.c:974 domain = 0x0 data = <optimized out> depth = <optimized out> log_func = 0x7f07b5e924c0 <g_log_default_handler> domain_fatal_mask = <optimized out> masquerade_fatal = <optimized out> test_level = <optimized out> was_fatal = <optimized out> was_recursion = <optimized out> msg = 0x13ee110 "Can not create directory '/var/lib/lightdm/.config/dconf': Permission denied" msg_alloc = 0x13ee110 "Can not create directory '/var/lib/lightdm/.config/dconf': Permission denied" i = 2 The owner and group of /var/lib/lightdm/.config were messed up. Searching for "dconf-service crashed with signal 5 in __libc_start_main" on the net shows many bug reports, so maybe this symptom has multiple causes. To find out, install libglib2.0-0-dbg to get a meaningful stacktrace. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/994064 Title: dconf-service crashed with signal 5 in __libc_start_main() To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/d-conf/+bug/994064/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs