docs: def shell_out(cmd, stderr=STDOUT, cwd=None):
      """Friendlier version of check_output."""
      if cwd is None:
          from os import getcwd
          cwd = getcwd()  # TODO do I need to normalize this on Windows
  
      out = check_output(cmd, cwd=cwd, stderr=stderr, universal_newlines=True)
      return _clean_output(out)