[已解决] 求教 predis 的一个错误

为啥下面的方法执行结果，会报

production.ERROR: ERR value is not an integer or out of range {"exception":"[object] (Predis\\Response\\ServerException(code: 0): ERR value is not an integer or out of range

<?php
public function incrAndExpire($key, $expire)
    {
        $script = <<<LUA
local current
local key = KEYS[1]
local expire_time = tonumber(ARGV[1])
current = redis.call("incr", KEYS[1])
if tonumber(current) == 1 then
    return redis.call("expire", key, expire_time)
else
    return 0
end
LUA;
        //return Redis::eval($script, $key, $expire); // 源代码
       return Redis::eval($script, 1, $key, $expire);
    }