:param bool dryrun: New value for runez.DRYRUN
    :return bool: Old value

def set_dryrun(dryrun):
    """
    :param bool dryrun: New value for runez.DRYRUN
    :return bool: Old value
    """
    r = _get_runez()
    old = r.DRYRUN
    r.DRYRUN = bool(dryrun)
    return old