Version: 1.1.4-1+b1
Severity: normal
Tags: upstream

plasma-discover freezes on startup when the packagekit backend is enabled. It used to work fine but now hangs (sometimes immediately, but always within a minute of being open) and has to be killed. This happens on both my Desktop and Laptop.
The daemon itself seems okay -- journal shows everything completing normally, no errors on the packagekit side.

What I'm seeing in plasma-discover's output is this repeated multiple times:
packagekitqt.offline: Properties could not be invalidated "org.freedesktop.PackageKit.Offline" QList("PreparedUpgrade")

I checked with busctl and PreparedUpgrade is false, so there's no pending upgrade. I confirmed with dbus-monitor that no PropertiesChanged signal is ever emitted on the Offline interface. The only PropertiesChanged signals come from the Transaction interface during get-updates. The "Properties could not be invalidated" error appears to be internal to the bindings' property cache rather than a response to a D-Bus signal.

The 1.3.6 changelog for packagekit only has a CVE fix, no D-Bus changes, so I think this is a bug in the bindings themselves rather than a daemon issue.

To reproduce: just launch plasma-discover. It freezes.

Workaround: Running "plasma-discover --backends flatpak-backend,fwupd-backend,kns-backend" in Konsole avoids the hang altogether.

Versions:
packagekit: 1.3.6-1
libpackagekitqt6-2: 1.1.4-1+b1 libqt6dbus6: 6.10.2+dfsg-16