def format_exc(exception: Exception, prefer_bare_message: bool = False) -> str:
    """
    Return a string representation of an exception.

    :param exception: The exception.

    :param prefer_bare_message:
        If True, only include the exception class if there is no message.
        This is more suitable for display to end users. (Default False.)
    """
    class_name = exception.__class__.__name__
    message = str(exception)
    if message:
        return message if prefer_bare_message else f"{class_name}: {message}"
    else:
        return class_name