$ sudo apt update
Get:1 http://deb.debian.org/debian bullseye InRelease [142 kB]
Err:1 http://deb.debian.org/debian bullseye InRelease
Unknown error executing apt-key
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
All packages are up to date.
W: An error occurred during the signature verification. The repository
is not updated and the previous index files will be used. GPG error:
http://deb.debian.org/debian bullseye InRelease: Unknown error
executing apt-key
W: Failed to fetch
http://deb.debian.org/debian/dists/bullseye/InRelease ; Unknown error
executing apt-key
W: Some index files failed to download. They have been ignored, or old
ones used instead.