KDE Neon Discover Stale Package Cache Refresh

Question

Discover Repository Cache in KDE Neon
On current KDE Neon User Edition releases, Discover maintains a local cache of repository metadata for APT, Flatpak, and Snap sources. The goal is to keep package listings consistent with current repository state after source changes.
It is unclear whether Discover automatically invalidates this cache when repository configuration changes, or which permission boundary controls cache refresh timing. This affects how quickly new updates appear in the graphical interface.
Does Discover refresh repository metadata automatically after sources.list or Flatpak remote changes? Is there a configuration option to force cache validation before displaying package results? Which user or system service owns cache invalidation?

Tasadduq Burney · Answer

Short answer
Discover does not automatically invalidate its repository metadata immediately after you change sources.list or modify a Flatpak remote. It relies on PackageKit, which refreshes on its own timer, so new packages can remain hidden until the next cycle or until you trigger a refresh manually. There is no user-facing configuration switch that forces validation before every search; you must invoke the refresh action or restart Discover.
Likely explanation versus confirmed facts
Likely explanation: Discover caches repository metadata through PackageKit for APT, Flatpak, and Snap back-ends. Editing system sources does not always send an invalidation signal to that cache, so the graphical list can stay stale for hours.
Confirmed facts: PackageKit runs as the system service packagekitd. Standard users can request a refresh, but Polkit may require authentication for system-wide source changes. Flatpak and Snap metadata are refreshed independently by their own runtimes and are not synchronized with APT refreshes performed by PackageKit.
Steps for this case

In Discover, click the refresh/reload button, or close and reopen the application.
Force an immediate APT metadata refresh through PackageKit:

pkcon refresh
Authenticate when prompted by Polkit.

If you changed a Flatpak remote, update that remote separately:

flatpak update
Then refresh Discover again.

Verify the refresh in the service log:

journalctl -u packagekitd -n 50
Assumptions and uncertainty
This answer assumes a standard KDE Neon User Edition installation with the PackageKit backend enabled. The exact default refresh interval is not fixed across stable, testing, and daily builds, so treat any multi-hour estimate as approximate. The packagekitd --refresh flag is not treated as reliable here; pkcon refresh is the safer, well-established command.
Missing diagnostic detail
Are you running KDE Neon User Edition stable, testing, or daily, and which Plasma version is installed? This determines whether the PackageKit timer behavior described here matches your release.

KDE Neon Discover Stale Package Cache Refresh

Discover Repository Cache in KDE Neon

1 answer

Short answer

Likely explanation versus confirmed facts

Steps for this case

Assumptions and uncertainty

Missing diagnostic detail

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