I am running backuppc-3.3.1-2 on a Debian/sid box, I am ssh-ing into the box and have a limited set of sudo commands that backuppc can execute. This is as opposed to ssh-ing in as root.
I have the following in my /etc/sudoers.d/backuppc account:
Cmnd_Alias BACKUP=/bin/tar, /usr/bin/rsync, /usr/bin/mysqldump, /usr/local/sbin/dbdump
backuppc ALL=NOPASSWD:BACKUP
Then I am able to run backups.
First step, can you ssh into the local host? Second step, can you simulate the backup command? In my case it is
/usr/bin/ssh -q -x farragut sudo /usr/bin/rsync --server --sender --numeric-ids --perms --owner --group -D --links --hard-links --times --block-size=2048 --recursive --checksum-seed=32761 --ignore-times . /