How to use the stestr.repository.util.get_repo_open function in stestr

will not print attachments on successful test execution.
    :param bool all_attachments: When set true subunit_trace will print all
        text attachments on successful test execution.
    :param bool show_binary_attachments: When set to true, subunit_trace will
        print binary attachments in addition to text attachments.

    :return return_code: The exit code for the command. 0 for success and > 0
        for failures.
    :rtype: int
    """
    if partial:
        warnings.warn('The partial flag is deprecated and has no effect '
                      'anymore')

    try:
        repo = util.get_repo_open(repo_type, repo_url)
    except repository.RepositoryNotFound:
        if force_init:
            try:
                repo = util.get_repo_initialise(repo_type, repo_url)
            except OSError as e:
                if e.errno != errno.EEXIST:
                    raise
                repo_path = repo_url or './stestr'
                stdout.write('The specified repository directory %s already '
                             'exists. Please check if the repository already '
                             'exists or select a different path\n'
                             % repo_path)
                exit(1)
        else:
            raise
    # Not a full implementation of TestCase, but we only need to iterate