[solved] Lightdm stops working after update yesterday

I have some systems running “testing” and some “stable”. About 14 days ago I was hit by an issue regarding login with lightdm at my “testing”-based systems: I can select user, I can apply password, but after hitting “ENTER” (or clicking on login button) nothing happens. I have made a workaround by using sddm instead of lightdm - that fixed the issue. Today this issue has arrived “stable”. I can no longer login into system using lightdm…

For those who are impacted by this too here my solution:

Change symbolic link /etc/systemd/system/display-manager.service
from /usr/lib/systemd/system/lightdm-plymouth.service
to /usr/lib/systemd/system/sddm-plymouth.service

It doesn’t matter if the “-plymouth” is in use or not - the issue exists with lightdm itself.

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You should use systemctl to manage that instead of doing it manually. Depending on if you have the plymouth version installed or not.

sudo systemctl enable sddm-plymouth.service -f

or

sudo systemctl enable sddm.service -f

As a side note, have you looked into why lightdm isn’t working instead of switching to sddm?

Yes, I tried to understand but I cannot identify the problem. There is absolutely nothing in the logs that points to an issue - but it is there and it is reproduceable (in the meantime on all 11 systems I own). And of course you are right in the way to fix it using my workaround! I know it is only a workaround but I cannot solve it otherway.

I have investigated a bit and found the following:
The issue only exists if lightdm-webkit2-greeter is used. I set debug=true in lightdm-webkit2-greeter.conf and now I can see the following in the logs:

Sep 25 09:33:30 arch-c2l systemd[1]: Starting Light Display Manager...
Sep 25 09:33:30 arch-c2l systemd[1]: Started Light Display Manager.
Sep 25 09:33:32 arch-c2l lightdm[961]: pam_unix(lightdm-greeter:session): session opened for user lightdm(uid=620) by (uid=0)
Sep 25 09:33:34 arch-c2l lightdm[1136]: pam_systemd_home(lightdm:auth): systemd-homed is not available: Unit dbus-org.freedesktop.home1.service not found.
Sep 25 09:34:37 arch-c2l lightdm[1136]: gkr-pam: unable to locate daemon control file
Sep 25 09:34:37 arch-c2l lightdm[1136]: gkr-pam: stashed password to try later in open session
Sep 25 09:34:38 arch-c2l lightdm[1136]: pam_unix(lightdm:session): session opened for user andreas(uid=1000) by (uid=0)
Sep 25 09:34:38 arch-c2l lightdm[1136]: pam_env(lightdm:session): deprecated reading of user environment enabled
Sep 25 09:34:38 arch-c2l lightdm[1136]: gkr-pam: unlocked login keyring

At the moment I do not know how to investigate more. Webkit2-greeter seems to be pretty old: it uses “antergos” theme. And webkit2 was updatet during the last days. Maybe the issue is related to lightdm-webkit2-greeter package.

The webkit2 greeter is long abandoned. It hasn’t had a commit in over 4 years.

It doesn’t seem like anyone else opened any bugs on Arch about it being broken. I am not sure if that is because it isn’t widely used or if your issue isn’t related to that package.

I can spin up a VM in a little while and test it for you.

It would be interesting if you can reproduce the issue. I have had used the combination lightdm/webkit2-greeter on all of my machines.

Yes, I can reproduce it.

I spent a bit of time looking at it. Narrowing down the packages upgraded and doing a little testing it is probably related either to the recent glib2 upgrade or the recent libwpe upgrade.

If you can reproduce it on Arch, you might consider filing a bug against the Arch package.

2 Likes

Thank you - I will check it out.

The issue is located in the webkit2gtk package. At this moment a downgrade to 2.36.7-1 solves the issue. Thanks for helping to identify this!

3 Likes

I’m having the exact same issue. Currently staring at a console deciphering how to switch to startX. I’ve been using webkit2-greeter for a while because I prefer the look better than slick-greeter.

I’m going to try switching the greeter back to slick-greeter. Should solve issue given the above. Still thinking of trying simpler login via xinit and startX.

Thanks guys for figuring this out!! :sunglasses::v::muscle:

1 Like

Note to self:
The name of a thing in a config file is often NOT the same as the file name.

Example:

slick-greeter

is

lightdm-slick-greeter

when used in lightdm.conf

What’s a few extra console logins and reboots, eh? :man_facepalming::man_facepalming::man_facepalming::rofl::rofl::rofl:
:v:

Simply downgrading webkit2gtk to 2.36.7-1 would do the job with webkitgreeter. I already have made a bug report on Arch bugs. It is not a problem of EndeavourOS - it is “upstream” :grin: