docs: def unpackexe(exefile, destdir):
      """Unpack the given exefile into destdir, using 7z"""
      nullfd = open(os.devnull, "w")
      exefile = cygpath(os.path.abspath(exefile))
      try:
          check_call([SEVENZIP, 'x', exefile], cwd=destdir,
                     stdout=nullfd, preexec_fn=_noumask)
      except Exception:
          log.exception("Error unpacking exe %s to %s", exefile, destdir)
          raise
      nullfd.close()