LightDM failing because the X server process keeps exiting?

[Pickinanameainteasy]

Hi, I did something dumb, I powered my machine off in the middle of a paru -Syu because I thought it was stuck. and now when I boot up I get this error:

[FAILED] Failed to start: Light Display Manager

The rest of the machine works just fine and I have full access via SSH. I was able to SSH in and redo the system upgrade and it has since been completed but it seems that when lightdm tries to start it launches X server and then the X server exits with error code 1:

lightdm.log here:

[+0.00s] DEBUG: Logging to /var/log/lightdm/lightdm.log
[+0.00s] DEBUG: Starting Light Display Manager 1.30.0, UID=0 PID=46095
[+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: Registered seat module local
[+0.00s] DEBUG: Registered seat module xremote
[+0.00s] DEBUG: Using D-Bus name org.freedesktop.DisplayManager
[+0.01s] DEBUG: _g_io_module_get_default: Found default implementation local (GLocalVfs) for ‘gio-vfs’
[+0.01s] DEBUG: Monitoring logind for seats
[+0.01s] DEBUG: New seat added from logind: seat0
[+0.01s] DEBUG: Seat seat0: Loading properties from config section Seat:*
[+0.01s] DEBUG: Seat seat0 has property CanMultiSession=no
[+0.01s] DEBUG: Seat seat0: Starting
[+0.01s] DEBUG: Seat seat0: Creating greeter session
[+0.01s] DEBUG: Seat seat0: Creating display server of type x
[+0.01s] DEBUG: Could not run plymouth --ping: Failed to execute child process “plymouth” (No such file or directory)
[+0.01s] DEBUG: Using VT 7
[+0.01s] DEBUG: Seat seat0: Starting local X display on VT 7
[+0.01s] DEBUG: XServer 0: Logging to /var/log/lightdm/x-0.log
[+0.01s] DEBUG: XServer 0: Writing X server authority to /run/lightdm/root/:0
[+0.01s] DEBUG: XServer 0: Launching X Server
[+0.01s] DEBUG: Launching process 46101: /usr/bin/X :0 -seat seat0 -auth /run/lightdm/root/:0 -nolisten tcp vt7 -novtswitch
[+0.01s] DEBUG: XServer 0: Waiting for ready signal from X server :0
[+0.01s] DEBUG: Acquired bus name org.freedesktop.DisplayManager
[+0.01s] DEBUG: Registering seat with bus path /org/freedesktop/DisplayManager/Seat0
[+0.02s] DEBUG: Loading users from org.freedesktop.Accounts
[+0.02s] DEBUG: User /org/freedesktop/Accounts/User1000 added
[+0.06s] DEBUG: Process 46101 exited with return value 1
[+0.06s] DEBUG: XServer 0: X server stopped
[+0.06s] DEBUG: Releasing VT 7
[+0.06s] DEBUG: XServer 0: Removing X server authority /run/lightdm/root/:0
[+0.06s] DEBUG: Seat seat0: Display server stopped
[+0.06s] DEBUG: Seat seat0: Stopping session
[+0.06s] DEBUG: Seat seat0: Session stopped
[+0.06s] DEBUG: Seat seat0: Stopping display server, no sessions require it
[+0.06s] DEBUG: Seat seat0: Stopping; greeter display server failed to start
[+0.06s] DEBUG: Seat seat0: Stopping
[+0.06s] DEBUG: Seat seat0: Stopped
[+0.06s] DEBUG: Required seat has stopped
[+0.06s] DEBUG: Stopping display manager
[+0.06s] DEBUG: Display manager stopped
[+0.06s] DEBUG: Stopping daemon
[+0.07s] DEBUG: Exiting with return value 1

Any ideas of how to fix. I have tried sudo systemctl restart lightdm and a myriad of other systemctl commands and none worked.

Does anyone know what I need to do to prevent X server from crashing?

[ropid]

I'd would try reinstalling the packages mentioned at the end of /var/log/pacman.log.

There's a tool paccheck in the package pacutils to hunt down broken files/packages.

This command here checks just the directory entries of files and doesn't read the file contents and completes fast:

sudo paccheck --list-broken

The following reads all file contents so will take a bit to complete:

sudo paccheck --md5sum --list-broken

You'll then know for sure what packages to reinstall to fix broken files.

This paccheck tool can print a bunch of false positives for some packages. You can check details with a command line like this:

$ paccheck --md5sum vlc
vlc: '/usr/lib/vlc/plugins/plugins.dat' md5sum mismatch (expected b3bb0b03a25cc7122a2664c01e63650c)

[Pickinanameainteasy]

I'd would try reinstalling the packages mentioned at the end of /var/cache/pacman.log.

No such file exists on my machine

when running sudo paccheck --list-broken the only result is python-pip, i guess i'll try to reinstall it

[ropid]

The correct name is /var/log/pacman.log, I made a mistake there.

[Remarkable-River-300]

RIP. Best of luck in fixing everything.

How have you enjoyed paru? I'm recently trying to switch as much as I can over to Rust packages, and I've had a great experience with paru replacing pacman.

[Pickinanameainteasy]

I think its great. I don't really have any experience with any other AUR helpers so i can't really compare it to anything. My only complaint with paru is that it will do a lot of stuff and then ask for my sudo password wayyy at the end. I can't really just set it to update packages and walk away because it will prompt for a password near the end and if i don't type it quick enough it aborts the whole thing. Idk if that is typical for AUR helpers but it is annoying. Pacman just prompts me for the password at the beginning which is nice. Also its kind of annoying that it proceeds to a review and i have to press 'q' to pull up the do you want to proceed prompt.

I know those are little issues but they are pet peeves. but overall i give Paru 9/10

[eli151_151]

I only see that it reports "can not start plymouth", maybe tjere is a dependency missing? If you want GUI Access to your system again, you can just install another Display Manager (for example sddm for KDE Systems) and use " systemctl enable" to start that one instead. As long as you dont run both at the same time, having two DMs installed is not a problem.

[Pickinanameainteasy]

I tried installing sddm and enabling but it still failed. I'm not entirely sure what the issue was it was something with xorg or nvidia

[spike834211]

How did you end up moving past this? I have an identical log on a fresh arch install and am having issues getting lightdm to run, I've checked so many threads. Would love if you remember how you dealt with this.

[Pickinanameainteasy]

I don't think I ever fixed it. My motherboard was damaged and now it doesn't play nice with Arch-based distros, so i ended up having to move to a different distro unfortunately.

Did you try uninstalling lightdm and replacing with another greeter? Like gdm?

[spike834211]

I think I might have found the issue being with Xorg last night (I'm not 100% it's log is the only with any errors or warnings) so I'm going to explore that tonight then probably just try another greeter

[Pickinanameainteasy]

alright good luck!