As this bugs is a request for the upstreamer I open an issue [1] and forward the request to this bug.
[1] https://github.com/rdiff-backup/rdiff-backup/issues/748 -- ⢀⣴⠾⠻⢶⣦⠀ Pablo Mestre Drake ⣾⠁⢠⠒⠀⣿⡁ -------------------------------------- ⢿⡄⠘⠷⠚⠋ https://debian.org ⠈⠳⣄⠀⠀⠀⠀ Debian, the universal operating system.
