KDE Plasma 6 and SDDM autologin workaround
KDE Plasma 6 and SDDM autologin workaround
Longtime Fedora Silverblue user here, who recently jumped over to Kinoite (Atomic KDE). I typically enable autologin on my display managers because I use whole disk encryption and already need to enter my passphrase to decrypt and start the OS.
I discovered pretty quickly that SDDM's autologin feature isn't working under Fedora 40. LightDM also failed to start under Wayland on F40, regardless of which greeter I tried.
Long story short, I opted to use GDM since I knew its automatic login feature worked fine under Wayland. It's worth noting that KDE has it's own lockscreen mechanism, so you won't even see GDM unless you manually logout of your session. To try this yourself:
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Install GDM:
rpm-ostree install --apply-live gdm -
Disable SDDM:
sudo systemctl disable sddm -
Enable GDM:
sudo systemctl enable gdm -
Reboot and select the Plasma session before logging in; this is required only once in order to establish to the default, otherwise GDM will load a broken GNOME session when autologin is enabled
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Edit
/etc/gdm/custom.confand add the following under[daemon](replacingusernamewith your own):AutomaticLoginEnable = true AutomaticLogin = username
Voila! You will no longer need to enter your user credentials before loading the desktop.
I must be lucky, works just fine for me with SDDM configured for Wayland only, autologin to a Wayland session.
max-p@media ~ % cat /etc/sddm.conf [Autologin] User=max-p Session=plasma #Session=plasma-bigscreen Relogin=true [General] DisplayServer=waylandSame here. No trouble with sddm.
Mind sharing what your distro and version are? The problem seems to be present on Fedora and OpenSUSE mostly, from what I can see of the issues posted online.
As far as I can tell, sddm.conf is the legacy conf location and the more recent SDDM/KDE versions are now placing the settings in /etc/sddm.conf.d/kde_settings.conf...not that that itself should matter much here.
Arch. That leads me to believe it's possibly a configuration issue. Mine is pretty barebones, it's literally just that one file.
AFAIK the ones in sddm.conf.d are for useful because the GUI can focus on just one file without nuking other user's configurations. But they all get loaded so it shouldn't matter.
The linked bug report seems to blame PAM modules, kwallet in particular which I don't think I've got configured for unlock at login since there's no password to that account in the first place.
If you want to interact as little as possible with the display manager, try using lightdm, it will also autologin and it's lighter than gdm.
That was my first choice alternative, but I had no success with any of the available LightDM greeters under Fedora 40 Kinoite (autologin, slick or gtk). They all resulted in a "Failed to start seat: seat0" error, even after ensuring
logind-check-graphical=truewas set. I may give it another go when I have the time.Oh I just installed lightdm in arch, disabled whatever I had, enables that service and activated the autologin by writing my username in some files I don't remember anymore. And that was it.
Due to some hardware issues I had I even had no service enabled and used to start it manually from a non GUI environment every time I logged on, and it worked fine. Now it's properly enabled though.
Unfortunately, that's where I started. Generally, Fedora would account for all of this by default, but even when adding these settings to the conf files as instructed, the result is the same...autologin is simply ignored and I'm met with the greeter upon reboot.
Check your journald logs, maybe some important information in there?
This bug is so old and tbh its a big f*** y** for KDE developement or whoever is responsible for this shitshow called SDDM. Its the reason my desktop pc is running LDM for multiple years now, since I stumbled over this.
But yeah, we need more KDE specific tools tralalala, instead of a working login manager.