Comment 0 for bug 1539811

This is a live USB environment (16.04, 2016-01-29 image). HP Envy x360 hybrid notebook. Package installed: 1.0.12+15.10.20150609-0ubuntu1 .

After installing the mir desktop session package and choosing "logout", the greeter correctly shows Unity8 as a login option. After entering "ubuntu" and a blank password, the screen goes to black (with backight), the fan runs for a few seconds of high activity, and no graphical session ever actually starts. The other tty screens remain available, and lightdm is eventually able to restart (though only after some time, and it is unclear if the commands to restart it are actually helping).

Some selected error messages from the time of session login:

*From lightdm.log*:
[+158.12s] DEBUG: Session pid=6899: Greeter requests session unity8-mir
[+158.12s] CRITICAL: g_dbus_connection_call_sync_internal: assertion 'object_path != NULL && g_variant_is_object_path (object_path)' failed

*From unity-system-compositor.log*:
dm_connection_start
ERROR: Throw location unknown (consider using BOOST_THROW_EXCEPTION)
Dynamic exception type: boost::exception_detail::clone_impl<boost::exception_detail::error_info_injector<boost::system::system_error> >
std::exception::what: write: Broken pipe
...
Closing session GDK-Mir
ERROR: /build/mir-UeyFew/mir-0.19.0+16.04.20160128/src/common/fatal/fatal.cpp(55): Throw in function void mir::fatal_error_except(const char*, ...)
Dynamic exception type: boost::exception_detail::clone_impl<boost::exception_detail::error_info_injector<std::runtime_error> >
std::exception::what: Couldn't clear output eDP-1 (drmModeSetCrtc = -13)

*From syslog*:
Jan 29 22:40:41 ubuntu org.freedesktop.Notifications[7323]: Failed to connect to Mir: Failed to connect to server socket: No such file or directory
Jan 29 22:40:41 ubuntu org.freedesktop.Notifications[7323]: Unable to init server: Could not connect: Connection refused
Jan 29 22:40:41 ubuntu org.freedesktop.Notifications[7323]: (notify-osd:7672): Gtk-WARNING **: cannot open display:
Jan 29 22:40:42 ubuntu dbus[1325]: [system] Activating service name='com.canonical.SystemImage' (using servicehelper)
Jan 29 22:40:42 ubuntu com.canonical.SystemImage[1325]: usage: system-image-dbus [-h] [--version] [-C DIRECTORY] [-v]
Jan 29 22:40:42 ubuntu com.canonical.SystemImage[1325]: system-image-dbus: error:
Jan 29 22:40:42 ubuntu com.canonical.SystemImage[1325]: Configuration directory not found: .load() requires a directory: /etc/system-image/config.d
Jan 29 22:40:42 ubuntu dbus[1325]: [system] Activated service 'com.canonical.SystemImage' failed: Launcher could not run (out of memory)