Some additional information about this bug : * bug appeared with Debian bookworm / rdiff-backup 2.2.x * rdiff-backup documentation about the CLI syntax change is available at https://github.com/rdiff-backup/rdiff-backup/blob/master/docs/migration.adoc#migration-from-old-to-new-cli * backupninja git tracker is at https://0xacab.org/liberate/backupninja but apparently doesn't allow registering for an account. I tried with several email addresses and always got « Email is not allowed for sign-up » * if you specify additional options for rdiff-backup in your backupninja config, for example « options = --no-acls », these options may not be valid for the "remove increments" command. in my case, I had to strip this option : removestr="$RDIFFBACKUP ${options/--no-acls/} remove increments --older-than $keep "
