The problem is, like the link ede posted stated, that gpg 2.1 retires passphrase from pipe for key auth.
The gpg agents needs to be enabled and configured for the restore to work.
Add the following to ~/.gnupg/gpg.conf
:
use-agent pinentry-mode loopback
And to your ~/gnupg/gpg-agent.conf
:
pinentry-program /usr/bin/pinentry-gtk-2 allow-loopback-pinentry
Then restart the agent with echo RELOADAGENT | gpg-connect-agent
.
The restore work even if the keys are only on the local machine. I still dont get why it does not ask for the passphrase when making incremental though.