Adding more data... I have been seeing this on bookworm (both the machine running "apt update" and the machine running apt-cacher-ng):
W: GPG error: http://deb.debian.org/debian bookworm-updates InRelease: The following signatures were invalid: BADSIG 0E98404D386FA1D9 Debian Archive Automatic Signing Key (11/bullseye) <ftpmas...@debian.org> E: The repository 'http://deb.debian.org/debian bookworm-updates InRelease' is not signed. On Fri, 28 Jan 2022 20:45:00 +0530 Pirate Praveen <prav...@onenetbeyond.org> wrote: > I have seen this on another sid chroot. So I had to remove > /var/lib/apt/* inside the chroot and debrepo/dists directory in > apt-cacher-ng's cache directory. I'm not sure if it can be fixed in > apt-cacher-ng. The above workaround has fixed it for me... for now. peace & happiness, martin