Usage: %s [<option>...] <old> <new-a> <new-b> [<out>]

Options:
  -m, --merge-prereleases  merge pre-releases together, ignores everything
                             after the last '~' in the version.
      --merge-unreleased   merge UNRELEASED entries together, ignoring their
                             version numbers.
  -?, --help               show this help message.
      --version            show the version.