Use workdir.options.path as a temporary working directory

def as_cwd():
    """ Use workdir.options.path as a temporary working directory """
    _set_log_level()
    owd = os.getcwd()
    logger.debug('entering working directory: ' + options.path)
    os.chdir(os.path.expanduser(options.path))
    yield
    logger.debug('returning to original directory: ' + owd)
    os.chdir(owd)