Must be an absolute path

def working_dir(val, **kwargs):  # pylint: disable=unused-argument
    '''
    Must be an absolute path
    '''
    try:
        is_abs = os.path.isabs(val)
    except AttributeError:
        is_abs = False
    if not is_abs:
        raise SaltInvocationError('\'{0}\' is not an absolute path'.format(val))
    return val