Tim,
Yes. I've completed installing Buster (belatedly) and I'm in the midst of reinstalling everything. I've updated sources.list and run apt-get update/upgrade.
This is the result when I try to add the keyring:
root@debian:/home/oneiric# apt-get update
. . .
W: GPG error:
https://apt.jenslody.de/stable stable Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY C5C6563A3CCA431B
E: The repository '
https://apt.jenslody.de/stable stable Release' is not signed.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(
manpage for repository creation and user configuration details.
root@debian:/home/oneiric# apt-get install jens-lody-debian-keyring
Reading package lists... Done
Building dependency tree
Reading state information... Done
E: Unable to locate package jens-lody-debian-keyring
root@debian:/home/oneiric#