QA: How can I prevent an individual App Center app from being upgraded?

[fdavid]

Question

How can I keep a specific App Center app on its currently installed version while continuing to update UCS and other apps? What is the difference between pin and stall, and do I still have to reject the app upgrade manually during univention-upgrade?

Answer

Use pin if a specific installed app must remain on its current version:

univention-app pin <APP-ID>

A pinned app cannot be upgraded or removed. To remove the pin again:

univention-app pin <APP-ID> --revert

However, pin does not prevent univention-upgrade from detecting and offering a newer version of the app. The upgrade search checks whether a newer App Center version exists independently of the pin state.

Therefore, if univention-upgrade asks whether the pinned app should be upgraded, answer n.

The important difference is that pin additionally prevents the actual upgrade from being performed. It therefore acts as a safeguard against accidentally upgrading the app, but it does not remove the interactive upgrade prompt.

stall serves a different purpose:

univention-app stall <APP-ID>

It sets the app status to stalled and disables its App Center repository component. It is primarily intended for apps that have reached end of life but shall remain installed, for example to suppress corresponding App Center warnings.

To undo this state:

univention-app stall <APP-ID> --undo

A stalled app can also still be detected as installed by the App Center upgrade search and a newer version may therefore still be offered by univention-upgrade. If this happens, the upgrade must likewise be rejected with n.

In short:

• pin: The update may still be offered. Answer n when prompted. The pin additionally blocks the actual upgrade and removal of the app.
• stall: The update may still be offered. Answer n when prompted. stall is intended primarily for keeping an end-of-life app installed and is not a hard upgrade protection comparable to pin.
• Neither pin nor stall reliably removes the app from the interactive upgrade questions of univention-upgrade.
• univention-upgrade --disable-app-updates skips App Center updates globally, but affects all installed apps and therefore cannot be used to exclude only one specific app.

Keeping an old app version does not guarantee compatibility with future UCS updates. Check the corresponding UCS and app update notes before updating the system.