[Solved] lightdm "failed to start session"

marol · 2022-09-21 10:52:54

About 2 weeks ago I had a problem after updates of my desktop and laptop.

After desktop update I couldn't make sudo operations - each time I tried to update or install something, I had only "Sorry, try again". Happily for me, it was solved after 2 days, when I made sudo -ll and then updated arch.
Now I can't solve problem with laptop, because I can't log in there. I reinstalled Arch (both comps have Arch, btrfs, lightdm and lightdm-slick-greeter), but I can log in there only with Ctrl+Alt+F2.
Yesterday I installed windows10 on the laptop and it worked, everyting worked as it should be. When I tried Artix (DE- Cinnamon), at first I could log in, but after sudo pacman -Syu I couldn't. I couldn't open folders. Reboot didn't helped. I thought may be there were some bugs in new Arch ISO, so I downloaded July iso. No, I was wrong. I reinstalled Arch, I already tried sddm, lightdm-gtk-greeter - situation is the same. The only difference with sddm - after entering password it opened light-grey screen and cursor arrow, which I could move. That's it. I removed sddm and installed lightdm (slick-greeter). I don't know what I did wrong?. Please, help me. I searched here and read a few topics about lightdm, they are similar to my problem, but unfortunately, it didn't work in my case.

I checked lightdm --test-mode --debug
Output:

[+0.00s] DEBUG: Logging to /home/olmar/.cache/lightdm/log/lightdm.log
[+0.00s] DEBUG: Starting Light Display Manager 1.32.0, UID=1000 PID=859
[+0.00s] DEBUG: Loading configuration dirs from /usr/share/lightdm/lightdm.conf.d
[+0.00s] DEBUG: Loading configuration dirs from /usr/local/share/lightdm/lightdm.conf.d
[+0.00s] DEBUG: Loading configuration dirs from /etc/xdg/lightdm/lightdm.conf.d
[+0.00s] DEBUG: Loading configuration from /etc/lightdm/lightdm.conf
[+0.00s] DEBUG: Running in user mode
[+0.00s] DEBUG: Registered seat module local
[+0.00s] DEBUG: Registered seat module xremote
[+0.00s] DEBUG: Using D-Bus name org.freedesktop.DisplayManager
[+0.02s] DEBUG: _g_io_module_get_default: Found default implementation gvfs (GDaemonVfs) for ?gio-vfs?
[+0.02s] DEBUG: Monitoring logind for seats
[+0.02s] DEBUG: New seat added from logind: seat0
[+0.02s] DEBUG: Seat seat0: Loading properties from config section Seat:*
[+0.02s] DEBUG: Seat seat0 has property CanMultiSession=no
[+0.02s] DEBUG: Seat seat0: Starting
[+0.02s] DEBUG: Seat seat0: Creating greeter session
[+0.02s] WARNING: Error getting user list from org.freedesktop.Accounts: GDBus.Error:org.freedesktop.DBus.Error.ServiceUnknown: The name org.freedesktop.Accounts was not provided by any .service files
[+0.02s] DEBUG: Loading user config from /etc/lightdm/users.conf
[+0.02s] DEBUG: User olmar added
[+0.02s] DEBUG: Seat seat0: Creating display server of type x
[+0.02s] DEBUG: Could not run plymouth --ping: Failed to execute child process ?plymouth? (No such file or directory)
[+0.02s] DEBUG: Seat seat0: Starting local X display
[+0.02s] DEBUG: XServer 1: Logging to /home/olmar/.cache/lightdm/log/x-1.log
[+0.02s] DEBUG: XServer 1: Writing X server authority to /run/lightdm/root/:1
[+0.02s] WARNING: Error reading existing Xauthority: Failed to open file ?/run/lightdm/root/:1?: Permission denied
[+0.02s] WARNING: XServer 1: Failed to write authority: Failed to open X authority /run/lightdm/root/:1: Permission denied
[+0.02s] DEBUG: XServer 1: Launching X Server
[+0.02s] DEBUG: Launching process 878: /usr/bin/X :1 -seat seat0 -auth /run/lightdm/root/:1 -nolisten tcp
[+0.02s] DEBUG: XServer 1: Waiting for ready signal from X server :1
[+0.02s] DEBUG: Acquired bus name org.freedesktop.DisplayManager
[+0.02s] DEBUG: Registering seat with bus path /org/freedesktop/DisplayManager/Seat0
[+0.02s] WARNING: Could not enumerate user data directory /var/lib/lightdm-data: Error opening directory '/var/lib/lightdm-data': Permission denied
[+0.02s] DEBUG: Process 878 exited with return value 1
[+0.02s] DEBUG: XServer 1: X server stopped
[+0.02s] DEBUG: XServer 1: Removing X server authority /run/lightdm/root/:1
[+0.02s] DEBUG: Seat seat0: Display server stopped
[+0.02s] DEBUG: Seat seat0: Stopping session
[+0.02s] DEBUG: Seat seat0: Session stopped
[+0.02s] DEBUG: Seat seat0: Stopping display server, no sessions require it
[+0.02s] DEBUG: Seat seat0: Stopping; greeter display server failed to start
[+0.02s] DEBUG: Seat seat0: Stopping
[+0.02s] DEBUG: Seat seat0: Stopped
[+0.02s] DEBUG: Required seat has stopped
[+0.02s] DEBUG: Stopping display manager
[+0.02s] DEBUG: Display manager stopped
[+0.02s] DEBUG: Stopping daemon
[+0.02s] DEBUG: Exiting with return value 1

Last edited by marol (2022-09-24 07:51:17)

kermit63 · 2022-09-21 11:55:34

WARNING: Error getting user list from org.freedesktop.Accounts: GDBus.Error:org.freedesktop.DBus.Error.ServiceUnknown: The name org.freedesktop.Accounts was not provided by any .service files

Do you have accountsservice installed? If not, try it out and see if it makes a difference.

V1del · 2022-09-21 12:54:53

That error should not be fatal to the DM starting. It seems like you might've broken your general permissions by running things as root that you shouldn't have. After booting into a failing lightdm change to a VT and post

sudo journalctl -b
sudo find ~olmar \! -user olmar -print

https://wiki.archlinux.org/title/List_o … n_services

marol · 2022-09-21 13:10:30

I installed it, but it made no difference. Now I see all other warnings without AccountsService.

...
[+0.01s] WARNING: Error reading existing Xauthority: Failed to open file ?/run/lightdm/root/:1?: Permission denied
[+0.01s] WARNING: XServer 1: Failed to write authority: Failed to open X authority /run/lightdm/root/:1: Permission denied
...
[+0.01s] WARNING: Could not enumerate user data directory /var/lib/lightdm-data: Error opening directory '/var/lib/lightdm-data': Permission denied

kermit63 · 2022-09-21 14:07:49

You should heed V1del's comments coz s(he) is definitely better at this than me.

marol · 2022-09-21 15:24:42

Thank you! So true! I know after I've read this forum since I moved to Arch
What is VT? May be tty2?

V1del · 2022-09-21 15:27:54

For example, or tty3 or whatever you can access assuming it's just lightdm failing to start.

marol · 2022-09-21 17:54:54

V1del wrote:

... After booting into a failing lightdm change to a VT and post
sudo journalctl -b
sudo find ~olmar \! -user olmar -print
https://wiki.archlinux.org/title/List_o … n_services

I tried, but the last command didn't work.
Here is the output of the first command.

V1del · 2022-09-21 18:19:15

Not seeing any obvious attempt at starting a session, do you get to lightdm and then thrown out when trying to log into a session? Which session are you trying to get into?

What does "didn't work" mean exactly? Did you get an error, if so which error. If it ran and executed properly but gave you no output then that's good and what we want to see.

FWIW there's also a lot of pager truncation going on, you shouldn't manually copy out of the terminal but e.g. use

sudo journalctl -b | curl -F 'file=@-' 0x0.st

and post the link you get.

Last edited by V1del (2022-09-21 18:23:00)

marol · 2022-09-21 19:32:35

V1del wrote:

Not seeing any obvious attempt at starting a session, do you get to lightdm and then thrown out when trying to log into a session? Which session are you trying to get into?

Yes, I do. I entered encryption key, then was lightdm, "Failed" then Ctrl+Alt+F2, so - I entered tty2 session.

V1del wrote:

What does "didn't work" mean exactly? Did you get an error, if so which error. If it ran and executed properly but gave you no output then that's good and what we want to see.

Yes, I mean there was no output.

V1del wrote:

FWIW there's also a lot of pager truncation going on, you shouldn't manually copy out of the terminal but e.g. use
sudo journalctl -b | curl -F 'file=@-' 0x0.st 
and post the link you get.

Ok. I'll try

loqs · 2022-09-21 19:40:26

Please also post the contents of /var/log/Xorg.0.log.
Edit:
The kernel messages from the journal showed i915, radeon and amdgpu modules were loaded. What GPU's are present in the system and which is the display atatched to?

Last edited by loqs (2022-09-21 19:51:29)

seth · 2022-09-21 20:06:48

Ftr, compare https://bbs.archlinux.org/viewtopic.php?id=279854 - there's also no attempt to log-in from lightdm logged; GDM seems to work.

seth · 2022-09-22 07:51:10

The other thread uses the webkit greeter and OP

slick-greeter-check-hidpi

=> Try the default gtk greeter.

marol · 2022-09-22 09:38:13

seth wrote:

The other thread uses the webkit greeter and OP
slick-greeter-check-hidpi
=> Try the default gtk greeter.

Thank you! I tried and it worked!
I'm not sure whether my issue is solved... I have to take a time to see what really happened, why it didn't start after update, after installing sddm, slick-greeter and few reinstallations...

Gy0m · 2022-09-23 14:40:26

I had the same issue today and i resolved it by

downgrade webkit2gtk

that was newly upgraded sep 21th and is required by lightdm-webkit2-greeter
Hope it can help some people here who are in the same case.

Last edited by Gy0m (2022-09-23 14:43:10)

xyz_max · 2022-09-24 03:40:42

Gy0m wrote:

I had the same issue today and i resolved it by
downgrade webkit2gtk
that was newly upgraded sep 21th and is required by lightdm-webkit2-greeter
Hope it can help some people here who are in the same case.

Thank you! Solved my problem

DarkSmile92 · 2022-09-27 08:01:41

Gy0m wrote:

I had the same issue today and i resolved it by
downgrade webkit2gtk
that was newly upgraded sep 21th and is required by lightdm-webkit2-greeter
Hope it can help some people here who are in the same case.

That also solved my issue, thanks a lot!

diapason · 2022-10-06 07:24:58

This post helped me after I suffered from the same bug.
Although that one: https://www.reddit.com/r/archlinux/comm … m_greeter/ gave me a 'better' fix?

Arch Linux

#1 2022-09-21 10:52:54

[Solved] lightdm "failed to start session"

#2 2022-09-21 11:55:34

Re: [Solved] lightdm "failed to start session"

#3 2022-09-21 12:54:53

Re: [Solved] lightdm "failed to start session"

#4 2022-09-21 13:10:30

Re: [Solved] lightdm "failed to start session"

#5 2022-09-21 14:07:49

Re: [Solved] lightdm "failed to start session"

#6 2022-09-21 15:24:42

Re: [Solved] lightdm "failed to start session"

#7 2022-09-21 15:27:54

Re: [Solved] lightdm "failed to start session"

#8 2022-09-21 17:54:54

Re: [Solved] lightdm "failed to start session"

#9 2022-09-21 18:19:15

Re: [Solved] lightdm "failed to start session"

#10 2022-09-21 19:32:35

Re: [Solved] lightdm "failed to start session"

#11 2022-09-21 19:40:26

Re: [Solved] lightdm "failed to start session"

#12 2022-09-21 20:06:48

Re: [Solved] lightdm "failed to start session"

#13 2022-09-22 07:51:10

Re: [Solved] lightdm "failed to start session"

#14 2022-09-22 09:38:13

Re: [Solved] lightdm "failed to start session"

#15 2022-09-23 14:40:26

Re: [Solved] lightdm "failed to start session"

#16 2022-09-24 03:40:42

Re: [Solved] lightdm "failed to start session"

#17 2022-09-27 08:01:41

Re: [Solved] lightdm "failed to start session"

#18 2022-10-06 07:24:58

Re: [Solved] lightdm "failed to start session"

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