Comment 2 for bug 562496

The problem is that there are *two* files created:
gpg: keyring `/root/.gnupg/pubring.gpg' created
gpg: /root/.gnupg/trustdb.gpg: trustdb created

So even if the --keyring is set, it'll still try to create
the config directory unless setting --trustdb-name too:
gpg --keyring /etc/apt/trusted.gpg --no-default-keyring --trustdb-name /etc/apt/trustdb.gpg --verify Release.gpg Release

So it probably needs to grow another setting ?

i.e. apt-deb "trustdb", right next to the "keyring"