Jtdcftul

I recently took the hint and upgraded from 16.04 LTS to 18.04 LTS, but had a nasty surprise when no login screen appeared, and even ctrl-alt F2 and friends didn't work. Fortunately, I was able to ssh in from elsewhere.

Welcome to Ubuntu 18.04.1 LTS (GNU/Linux 4.15.0-33-generic x86_64)

Looking at syslog, I saw that gdm3/wayland tried repeatedly to start org.freedesktop.systemd1 and it would immediately fail (exit 1). A message like this would be repeated over and over in syslog.

Aug 30 09:13:38 pabst /usr/lib/gdm3/gdm-wayland-session[1442]: dbus-daemon[1444]: [session uid=127 pid=1444] Activating service name='org.freedesktop.systemd1' requested by ':1.0' (uid=127 pid=1442 comm="/usr/lib/gdm3/gdm-wayland-session gnome-session --" label="unconfined")

Aug 30 09:13:38 pabst /usr/lib/gdm3/gdm-wayland-session[1442]: dbus-daemon[1444]: [session uid=127 pid=1444] Activated service 'org.freedesktop.systemd1' failed: Process org.freedesktop.systemd1 exited with status 1

Aug 30 09:13:38 pabst /usr/lib/gdm3/gdm-wayland-session[1442]: Unable to register display with display manager

Aug 30 09:13:38 pabst gdm3: Child process -1442 was already dead.

Aug 30 09:13:38 pabst gdm3: Child process 1439 was already dead.

Aug 30 09:13:38 pabst gdm3: Unable to kill session worker process

Seeing advice elsewhere, I tried using "ubuntu-drivers autoinstall" which installed the recommended nvidia-driver-390.
That didn't help.

I also tried disabling Wayland in a configuration file,
but also no good.

I purged the Nvidia driver and tried with nouveau. Still no dice.

Then I installed nvidia-340 which at least sets the
screen resolution correctly (as seen using "xinit" which
brings up an xterm without a display manager).

Then I installed xdm, and made "xdm" the default greeter
(it was part of the configuration when xdm was installed).

Now a login screen appears (and ctrl-alt F2 and friends work)
but if I try to log on, it waits a bit after the login and then
bumps back to the login screen.

.xsession-errors shows no serious problems.

But syslog shows that gnome-session-binary is trying to start org.freedesktop.systemd1 which (of course) fails again, which makes the required Gnome Shell.desktop die which causes the whole shebang fail (after lots of futile tries).

The sad ending to the story:

Aug 30 11:40:12 pabst dbus-daemon[3966]: [session uid=820 pid=3964] Activated service 'org.freedesktop.systemd1' failed: Process org.freedesktop.systemd1 exited with status 1

Aug 30 11:40:12 pabst gnome-keyring-secrets.desktop[4042]: GNOME_KEYRING_CONTROL=/home/john/.cache/keyring-DFQHOZ

Aug 30 11:40:12 pabst gnome-keyring-secrets.desktop[4042]: SSH_AUTH_SOCK=/home/john/.cache/keyring-DFQHOZ/ssh

Aug 30 11:40:12 pabst org.gnome.Shell.desktop[4057]: Window manager warning: Unsupported session type

Aug 30 11:40:12 pabst gnome-session[3926]: gnome-session-binary[3926]: WARNING: App 'org.gnome.Shell.desktop' exited with code 1

Aug 30 11:40:12 pabst gnome-session-binary[3926]: WARNING: App 'org.gnome.Shell.desktop' exited with code 1

Aug 30 11:40:13 pabst org.gnome.Shell.desktop[4060]: Window manager warning: Unsupported session type

Aug 30 11:40:13 pabst gnome-session[3926]: gnome-session-binary[3926]: WARNING: App 'org.gnome.Shell.desktop' exited with code 1

Aug 30 11:40:13 pabst gnome-session[3926]: gnome-session-binary[3926]: WARNING: App 'org.gnome.Shell.desktop' respawning too quickly

Aug 30 11:40:13 pabst gnome-session[3926]: gnome-session-binary[3926]: CRITICAL: We failed, but the fail whale is dead. Sorry....

Aug 30 11:40:13 pabst gnome-session-binary[3926]: Unrecoverable failure in required component org.gnome.Shell.desktop

Aug 30 11:40:13 pabst gnome-session-binary[3926]: WARNING: App 'org.gnome.Shell.desktop' exited with code 1

Aug 30 11:40:13 pabst gnome-session-binary[3926]: WARNING: App 'org.gnome.Shell.desktop' respawning too quickly

Aug 30 11:40:13 pabst gnome-session-binary[3926]: CRITICAL: We failed, but the fail whale is dead. Sorry....

So:
(1) Can org.freedesktop.systemd1 be fixed? Is there any way to see why it's failing? or if it's unfixable
(2) Is there a way to have gnome use something other than org.freedesktop.systemd1 ? or
(3) Is there a display manager I can use on Ubuntu bionic that doesn't use any gnome stuff?

I think you need to select Xorg from Xwayland, see this bug

Edit your /etc/gdm3/custom.conf file and add :

WaylandEnable=false

another user issue had fixed after install haveged, may you can try :

sudo apt install haveged

and also you need make sure had plymouth package.

sudo apt install plymouth

and also you might make sure your kernel fixed, see this bug

Hope this helps.

I had a similar issue, do not know if this is exactly the way to fix this but it worked. I added this line to /etc/pam.d/gdm-launch-environment (adding to /etc/pam.d/common-session worked as well):

session optional        pam_systemd.so

I do not know if it should have been there in 16.04, or if something with the 16.04 to 18.04 upgrade was skipped.
It was this error in syslog that finally lead me to this fix:

(EE) systemd-logind: failed to get session: PID 10023 does not belong to any known session

As a result of that, gdm-x-session failed and aborted, and the gdm3 service just kept trying over and over again, flooding my syslog.