[Fixed] Can't log in after suspending Xubuntu 20.04
Tagged: learning linux
(It's funny that this will be my first post of 2021)
My laptop at home is a Thinkpad T470 running Xubuntu 20.04, upgraded from 18.04 after that was upgraded from 16.04. Everything worked fine, including the printing service(!), except...
Except I couldn't log in after suspending the system. I just refrained from ever using the suspend feature. Until today.
Here's how the problem manifested:
- Hit the suspend button from the GUI.
- After a few seconds, screen goes blank and the power button begins pulsing slowly, signalling the machine is suspended.
- Press the power button, get a log in screen. It has a password input and three buttons: switch user, cancel, and unlock.
- Enter password, hit unlock. Screen goes blank for a second.
- I'm back at the prompt, but now I can't input anything into the password field.
Here's what a I tried:
- Trigger the bug. Hit ctrl+alt+F3 to get a terminal. Turn on tmux and tail the following logs:
/var/log/lightdm/lightdm.log. See a few warnings and errors, investigate, but come up with nothing related to my problem.
- Remove lightdm-gtk-greeter and lightdm-gtk-greeter-settings:
apt-get remove lightdm-gtk-greeter lightdm-gtk-greeter-settings. Trigger bug: same thing happens. Except now the login prompt looks different. Eh.
- Trawl through launchpad bugs and ubuntu forums and notice someone having a similar problem with light-locker and xscreensaver. Decide to uninstall light-locker and reinstall xfce4-screensaver:
apt-get remove light-locker xfce4-screensaver && apt-get install xfce4-screensaver. Trigger bug, input password and... success!.
I'm not sure what was the exact problem was, but I strongly suspect that it has something to do with light-locker. Anyway, hope this helps anyone else that gets stuck on this issue.