Good morning.

Any attempt to run “apt update” or to update in aptitude fails with the same error for each repository:

“Err:4 http://ftp2.fr.debian.org/debian testing InRelease
gpgv, gpgv2 or gpgv1 required for verification, but neither seems installed”

However, gpgv2 is installed, currently version 2.2.27.

How can this situation be rectified?

Have you tried changing repos?

I use the default for France and one alternative repository. Both fail, together with the repository of the SoftMaker Office-Suite, deb-multimedia.org, deb-torproject.org and one German repository, which I had added for security a long time ago. Also, I am currently on a different but identically equipped machine, where the update works with the exact same repositories *).

It is highly probable that something is misconfigured on the system in question. I have thought about libraries which may cause trouble, but this is just a wild guess: I have, in the past, compiled GnuPG from sources, meaning that also libgcrypt, libgpg-error, libksba and libassuan were frequently updated from self-compiled packages. As I use the PORG package-organizer for such programs, they could be uninstalled, when I returned to the official versions from the Debian resources.

On the other hand, re-installing a package should in my opinion also replace the dependencies, if they must be updated.

If I am not clear, this may be the origin of many problems, maybe also the one that I am dealing with, right now. But I am far from sure and prefer that you assume that I do not have a clue... or have I?

*) Edit: torproject.org fails because I have not updated their signature key. But that is a different problem.

The “solution” was to uninstall everything which appears to have a connection with GnuPG and does not cause other conflicts, then to install gpgv1 without calling `apt update`, first (it would not have worked anyway). After that, update and upgrade were executed and I could even re-install gpgv2.

All's fine, as usual.