Panel stuck on "Restart to install pending updates" when no offline update is available #233

What Happened?

The System Settings -> System panel shows "Restart to install pending updates", but when I open the Shut Down dialog from Quick Settings, there is no "Install pending system updates" option.

The reason seems to be that there are no prepared offline updates on the system: pkcon offline-get-prepared reports "No offline updates have been prepared" and /var/lib/PackageKit/prepared-update does not exist. So the Shut Down dialog is correct and the panel is showing a stale state.

The panel never recovers on its own, only restarting the daemon (systemctl --user restart io.elementary.settings-daemon) or rebooting clears it.

Steps to Reproduce

1. Let updates download so the System panel shows "Restart to install pending updates" (the Shut Down dialog shows "Install pending system updates" at this point too).
2. Make the prepared offline update go away without triggering it from the Shut Down dialog (e.g. run sudo apt upgrade, or run sudo pkcon offline-cancel)
3. Open the System panel: it still shows "Restart to install pending updates".
4. Open the Shut Down dialog: there is no "Install pending system updates" option.

Expected Behavior

When there are no prepared offline updates, the System panel and the Shut Down dialog should agree. The panel should not keep saying a restart is required to install pending updates when nothing is actually prepared to install.

OS Version

8.x (Circe)

OS Architecture

amd64 (on most hardwares)

Session Type

Secure Session (Wayland, This is the default)

Software Version

Latest release (I have run all updates)

Log Output

Hardware Info

No response