Seems I'm running out of money on my account, so I wanted to go ahead and nuke what I had, except I'm unable to at this time:
/usr/bin/tarsnap --key tarsnap.key --cachedir .tarsnap-cache --fsck
tarsnap: Connection lost, waiting 30 seconds before reconnecting
tarsnap: Error reading cache directory from /root/.tarsnap-cache
tarsnap: Error generating archive statistics
tarsnap: Error exit delayed from previous errors.
Not quite sure how to debug... so far I've reinstalled tarsnap via the deb package, but that didn't work.