Invalid or corrupted package (PGP signature) --- Why

The other day while updating one of my machines, the power plug fell out while downloading the packages to be updated (unplugging a deceased rodent was the final straw but it must have worked loose over time).

After removing the database lock file, I was and to rerun pacman -Syu but all of the packages then reported an invalid PGP signature!

I was able to correct the problem by following the instructions in this thread.

I am however mystified as to why a power interrupt should cause such a problem, especially during the download phase. It might make sense if the fail was in the install phase, or for a single package (the one being downloaded).

Any ideas?

If you provide some logs you might stand a better chance of a useful response.

journalctl --boot=-1 --priority=3 --catalog --no-pager


Cache is a plausible explanation - but one cannot know for sure.

The kernel agressively caches everything and going cold with a lot of data cached - yes possible.

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And it may also depend on the filesystem used.

The file systems all have some protection against problems after a power failure.
However, this protection varies depending on the file system.

FAT has next to no protection. :wink:
Other file systems use log files and/or checksums. Sometimes this helps to restore a previous good situation. (but not always)
Some file systems can create snapshots. Then a rollback to “before the update” is possible

Something like this works, for example, with Timeshift / snapper and btrfs.

You find good Information about Btrfs in the wiki



Thanks for the ideas.
I was really only wondering if there was an obvious reason, rather than asking anyone for a deep dive into the issue, that’s why I didn’t put any details.

FWIW: journalctl for the relevant boot had only one line – a complaint about unable to enumerate a USB device (i.e. the dead rodent). And the FS is EXT4.

Perhaps this helps:

Logs and other information are what we generally rely on to find the likely cause of an issue, obvious or not; as is said ‘the devil is in the details’. Without that, we’re mostly peeing into the wind.

If interrupted during the download phase, an update can usually be recovered without any great issue; you obviously realize that. However, it’s always possible a loss of power will affect something else in your system. Just what may have been affected, is a little harder to guess.

A cache issue as suggested by @linux-aarhus is as plausible as anything else. The following links may be helpful in that regard:

According to my understanding is that it happens when you don’t keep your system updated.

Mainly from what I’ve seen here, but also due to the fact that I update religiously and have never seen it…