For updating distro packages, Discover generally uses the PackageKit library which abstracts the difference between different package management tools. This library uses distro-specific plugins to provide a consistent interface to Discover.
pkcon is the command-line interface to PackageKit. It will do the same things Discover does (roughly).
On immutable OS distros, Discover generally has a dedicated distro-specific backend instead, since PackageKit. I’m aware of two: one for SteamOS and one for Fedora Kinoite.
It means PackageKit’s author and former maintainer stopped working on it very regularly and decided unfortunately to publicly communicate this in a FUD-generating matter. The software still generally works. The trends that Richard points out are real, but it’s also premature to declare the library useless because we definitely haven’t moved into a world where it no longer has any value.
I’m still wondering how the offline-update works. Does it basically do the following:
- At systemd startup, see there’s packages to be updated - Boot just enough to be able to update the system - Update them using whaetever packagemanager the system uses. - If there are failures, rollback. - If there are no failures, restart system after installation and boot as normal.
Or am I way off?
Edit: Seems I wasn’t too far off. Read the link in the post below for explanation