Lock screen is shaking after update to Plasma 6.1

Help
1

After I updated to plasma 6.1, lock screen is completely broken, it continue to shake and show "unlocking failed”, but I am not able to input any password. The only way is to switch session and unlock with loginctl unlock-session.

I am using Gentoo with X server, no wayland.

As I see I am not the only one, this issue has been reported before:
url:resolved-plasma-6-lock-screen-repeatedly-shakes-and-says-unlocking-failed/13754/2

But I don’t want reinstall any package, I would like to understand the root cause of the issue , any help would be appreciated for the investigation.

2

Hi - what do your system journal logs say around the time when the lock screen malfunctions? Entries from kscreenlocker_greet would be the most immediate ones to look for as that’s what’s directly operating the lockscreen, but there may be a chance that some other system component related to authentication or session management is causing errors that are twisting back around and throwing things off.

3

I don’t have journal logs because I am using openRC, I tried to search in syslog but I don’t see any relevant log, and nothing related kscreenlocker_greet.

Dec  8 04:02:00 localhost CROND[9096]: (root) CMD ([ ! -f /etc/cron.hourly/0anacron ] && run-parts /etc/cron.daily)
Dec  8 04:02:00 localhost CROND[9095]: (root) CMDEND ([ ! -f /etc/cron.hourly/0anacron ] && run-parts /etc/cron.daily)
Dec  8 04:22:00 localhost CROND[11000]: (root) CMD ([ ! -f /etc/cron.hourly/0anacron ] && run-parts /etc/cron.weekly)
Dec  8 04:22:00 localhost CROND[10999]: (root) CMDEND ([ ! -f /etc/cron.hourly/0anacron ] && run-parts /etc/cron.weekly)
Dec  8 05:01:00 localhost CROND[14760]: (root) CMD (run-parts /etc/cron.hourly)
Dec  8 05:01:00 localhost CROND[14759]: (root) CMDEND (run-parts /etc/cron.hourly)
Dec  8 06:01:00 localhost CROND[21274]: (root) CMD (run-parts /etc/cron.hourly)
Dec  8 06:01:00 localhost CROND[21273]: (root) CMDEND (run-parts /etc/cron.hourly)
Dec  8 07:01:00 localhost CROND[27568]: (root) CMD (run-parts /etc/cron.hourly)
Dec  8 07:01:00 localhost CROND[27567]: (root) CMDEND (run-parts /etc/cron.hourly)
Dec  8 08:01:00 localhost CROND[3509]: (root) CMD (run-parts /etc/cron.hourly)
Dec  8 08:01:00 localhost CROND[3508]: (root) CMDEND (run-parts /etc/cron.hourly)
4

Maybe dbus-monitor logs can be useful?

the file is too big and I can’ add links, but this is the log: pastebin[dot]com/dQdz4kYB

5

I found in /usr/share/plasma/shells/org.kde.plasma.desktop/contents/lockscreen/LockScreenUi.qml

That the problem is caused by someone calling onFailed, this will show the message “unlocking failed” and start the animation in a loop.

Now I still don’t understand what is the cause of the failure, but for sure this behavior is wrong and I consider it a bug.

This is onFailed can be triggered for any kind of error (not only if I am trying to unlock), in my case is shown even if I don’t provide any input.
So display the message “Unlocking failed” is completely misleading, it should be shown only when the user tried to unlock the screen.
And also is wrong to start the animation in a loop blocking any user interaction.

If I remove this stupid rejectPasswordAnimationStart(); I can finally input the password and interact with the lock screen, unfortunately unlocking still is not working, but it’s expected because I didn’t fix the root cause of the error, but at least I can Interact.

So now just by disabling rejectPasswordAnimationStart, I can click on switch user and login again, not a solution but a good workaround.

6

Seems like some possibly similar issues experienced by Gentoo users have been solved by recreating files associated with PAM? Gentoo Forums :: View topic - kscreenlocker_greet and the contents of /etc/pam.d/kde

Or with making sure all Qt components installed have matching versions? Gentoo Forums :: View topic - [SOLVED] screen locker broken after recent qt upgrade

With a distro with such an intricate and local-machine-dependent package install/update process, it may be hard for folks here to dive deep into what happened on your specific system during the most recent updates. I understand not wanting to wipe and reinstall an entire system, but it sounded like some folks had good luck in similar cases with reinstalling specific related components like kscreenlocker, PAM, etc.