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:

  1. Install GDM: rpm-ostree install --apply-live gdm

  2. Disable SDDM: sudo systemctl disable sddm

  3. Enable GDM: sudo systemctl enable gdm

  4. 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

  5. Edit /etc/gdm/custom.conf and add the following under [daemon] (replacing username with your own):

     AutomaticLoginEnable = true
 AutomaticLogin = username

Voila! You will no longer need to enter your user credentials before loading the desktop.

  • @[email protected]OPEnglish
    1•4 months ago

    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.

    • @KlavKalashj
      1•4 months ago

      I am using Fedora 40 Kinoite with autologin on SDDM, no trouble and never had.

      • @[email protected]OPEnglish
        1•4 months ago

        Interesting. I followed the documentation from the various distros (Arch, Debian, and openSUSE), and added the following to /etc/sddm.conf.d/10-autologin.conf:

        [Autologin]
Relogin=false
Session=plasma (I've also tried plasma.desktop here)
User=thayer

        I’ve confirmed that plasma.desktop exists in /usr/share/wayland-sessions/ and it’s the session I normally select regardless of DM used.

        I’ve also tried placing the autologin text in /etc/sddm.conf, /etc/sddm.conf.d/autologin, and the default /etc/sddm.conf.d/kde_settings.conf. No matter where it’s saved, the settings are ignored and I’m brought right back to the greeter upon reboot. Nothing is logged in journald and SDDM doesn’t write to its own log in /var/log.

        I’ve also tried the above with and without the KDE Wallet service enabled (I normally keep it disabled).

        If I use the System Settings GUI to set the above details (via Colors & Themes > Login Screen (SDDM) > Behavior), the System Settings app crashes upon close. I’ve had multiple updates since rebasing to Kinoite, so the chance of a corrupted package is nil.

        Something is definitely afoot.

    • Max-P
      1•4 months ago

      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.

      • RustmilianEnglish
        1•4 months ago

        I have kwallet setup with a password and it unlocks automatically with auto login. idk why, it’s not like I configured anything. I’m using the QT6 version. When I was using the QT5 version I had to configure it, but since switching I’ve removed those configs. Perhaps it’s because it’s the same password as the user…

        • Max-P
          1•4 months ago

          That’s weird because the whole idea is that it shares the same password so it can unlock it as you log in. The password is not available during autologin because well, that’s the whole point to not provide a password. So you either have no password on kwallet or you’re not auto logging in.

      • @[email protected]OPEnglish
        1•4 months ago

        Thanks for the info. I don’t enable the Kwallet service at all either, so I don’t think that would be it, but who knows. At any rate, I rechecked my config and even moved the settings to /etc/sddm.conf without success. It seems I’m not alone at least, so I’ll just stick with GDM until I can troubleshoot further.