26s login delay on Plasma 6.6 (Fedora 43 Rawhide) - xdg-desktop-portal timeout

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Since updating to Fedora 43 with Plasma 6.6.0.1, I am experiencing a severe performance issue during the transition from SDDM to the desktop. There is a consistent ~26-second hang. Additionally, there is a ~10-second delay with a frozen cursor before the SDDM login screen even appears.

Hardware & System Specs

  • Device: Lenovo IdeaPad Flex 5 14IAU7

  • CPU: Intel Core 12th Gen (Alder Lake)

  • GPU: Intel Iris Xe Graphics

  • Kernel: 6.18.12-200.fc43.x86_64

  • OS: Fedora 43

  • DE: KDE Plasma 6.6.0.1 (Wayland session)

The output of systemd-analyze --user blame clearly points to a portal timeout:

Plaintext26.134s xdg-desktop-portal.service 25.494s plasma-kcminit.service 1.395s plasma-powerdevil.service 173ms plasma-ksmserver.service 165ms plasma-xdg-desktop-portal-kde.service

System-level blame shows fast boot times for devices, suggesting the issue is purely within the D-Bus/Portal communication layer.

What I have already tried:

  1. Portal Configuration: Created ~/.config/xdg-desktop-portal/portals.conf with default=kde, but it seems to be ignored.

  2. Backends: Reinstalled xdg-desktop-portal-gtk and even tried truncating the gtk.portal file to 0 bytes—no change in timeout duration.

  3. KWallet: Disabled KWallet to rule out secret-service timeouts.

  4. Network: Disabled NetworkManager-wait-online.service.

  5. Cache: Cleared ~/.cache/plasma* and ~/.cache/xdg-desktop-portal*.

  6. Systemd Override: Tried setting TimeoutStartSec=3s for xdg-desktop-portal.service, but the internal D-Bus timeout seems to override this or cause other services to wait regardless.

After the kernel logs, the system hangs with a static cursor for ~10 seconds before SDDM appears. After login, the wallpaper is visible but the shell (panels, wallpaper, etc.) takes exactly 26 seconds to become interactive.

Is there a known regression in dbus-broker or xdg-desktop-portal in Rawhide that causes it to ignore portals.conf or wait for a non-responsive GTK/KWallet backend in a Wayland Plasma session? Any advice on how to further debug the D-Bus message traffic during these 26 seconds?