[Cloudynitzar] - Adding Clommunity repository GPG key to the local APT keyring...
gpg: directory '/root/.gnupg' created
gpg: keybox '/root/.gnupg/pubring.kbx' created
gpg: keyserver receive failed: No data
and later:
[Cloudynitzar] - Updating package sources with newly added repositories...
W: GPG error: http://repo.clommunity-project.eu/debian unstable/ Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY D246F495A59C5DC8
W: The repository 'http://repo.clommunity-project.eu/debian unstable/ Release' is not signed.
Fresh Debian 9 Stretch on a CubieTruck board:
and later: