Run real rsync into a temp dir to test hard links, keep, remove-before-backup, stray files in the backup dir and the old folder name format, and use a fake Popen to test how rsync return codes are handled.
Run real rsync into a temp dir to test hard links, keep, remove-before-backup, stray files in the backup dir and the old folder name format, and use a fake Popen to test how rsync return codes are handled.