When the backup root (i.e., live data) is accessed over sftp, obnam queries the local system for the names of the user and group. This is going to result in bad data. In this case, unless it can query the remote server, it should just not store the username and groupname at all. --liw
Fixing this is going to require an obnam server mode, where the remote side is also running obnam, and we can query that for stuff. But then SFTP as a whole will be unnecessary. --liw