It appears that the examples to "lists the times of the available versions of the file ..." in section 6 (Getting information about the backup directory) in the "Usage examples" page (https://rdiff-backup.net/examples.html#getting_information_about_the_backup_directory) have gotten mangled. The two examples (old and new) look like
rdiff-backup --list-increments out-dir/filerdiff-backup -l out-dir/file rdiff-backup list increments out-dir/filerdiff-backup -l out-dir/file which don't look right and the old example (I only have 2.0.5 installed on the machine where I need this) doesn't seem to work when I try to modify it for the file I'm looking for.