Devuan signing key doesn't get passed to apt keyring.
After the update to devuan-keyring_2016.10.10_all.deb, my two Jessies failed to
apt-get update with the following error:
W: GPG error: http://de.mirror.devuan.org jessie InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 94532124541922FB
The key exists in /usr/share/keyrings/devuan-keyring.gpg, but not in /etc/apt/trusted.gpg, so the command
$ gpg --keyring /usr/share/keyrings/devuan-keyring.gpg --export 94532124541922FB | apt-key add -
fixes the issue locally.