> However, it has exactly the same behaviour as the -D
> flag. It goes up and downloads the siblings folders
> if the first url does not end with a /, and it does
> not goes up if the URL ends with a /.


Yes, I screwed the option ; the correct one is:

httrack <https://dist.apache.org/repos/dist/dev/commons/dbcp> -O /tmp/dist -*
+dist.apache.org/repos/dist/dev/commons/dbcp/*