Shapes that are legal and rare, so nothing routine exercises them: two variadics, a stacked short
cluster, an option repeated to a count, a `[options]` beside spelled-out options, and a usage line
continued onto the next line.

Usage:
  odd -vvv
  odd (--from=<a>
       --to=<b>)
  odd [options] gather <src>... <dst>
  odd tag <name>... -- <rest>...
  odd -

Options:
  -v             Verbosity, repeatable.
  --from=<a>     Source.
  --to=<b>       Target.
  --dry-run      Say what would happen.
  --force        Do it anyway.
