Usage: subunit2disk [options]

Export a subunit stream to files on disk.

Options:
  -h, --help            show this help message and exit
  -d DIRECTORY, --directory=DIRECTORY
                        Root directory to export to.

Creates a directory per test id, a JSON file with test metadata within that directory, and each
attachment is written to their name relative to that directory.  Global packages (no test id) are
discarded.  Exits 0 if the export was completed, or non-zero otherwise.