在用云函数定时触发器开发消息订阅功能时，遇到一个问题。

环境：基础版本库2.17.0

在定时器函数中，调用另外一个云函数，该云函数中调用了cloud.openapi.subscribeMessage.send。在云函数日志端显示函数调用失败，但是在微信里可以收到一条订阅消息。二其它的订阅消息就无法收到。日志显示异常信息如下：

exception occured {

"errCode": -504002,

"errMsg": "callFunction:fail -504002 functions execute fail. requestID t_1647352800638_12041-17f8de0ebd5_2, TypeError: Do not know how to serialize a BigInt\n at JSON.stringify (<anonymous>)\n at callback (/var/runtime/node12/CallbackContext.js:31:23)\n at /var/runtime/node12/CallbackContext.js:81:16\n at /var/runtime/node12/Runtime.engine.js:237:13\n at processTicksAndRejections (internal/process/task_queues.js:97:5)"

出现问题的云函数代码如下：

const cloud = require('wx-server-sdk')

cloud.init({

env:cloud.DYNAMIC_CURRENT_ENV

});

const GOOD_GIFTS = [

{

"type":"每周好物推荐",

"title":"适合送给亲人和朋友的德尔玛加湿器",

"notify":"每周五晚19:00准时更新",

"date":"2022-03-25",

// "abstract":"德尔玛加湿器"

"abstract":"比京东同款便宜约20%~30%"

}

];

/*

the procedure:

1.get all the subscriber's openid

2.send the notify message to every subscriber

*/

exports.main = async (event, context) => {

// get openid

const allOpenid = await cloud.callFunction({

name:"getAllOpenid",

});

if( allOpenid == null )

return;

// get all the subscribers's openid array

candidateSets = allOpenid.result.data;

console.log("candidateSets = ",candidateSets);

for( let i = 0; i < candidateSets.length; i++){

console.log("sending the subscribe messege to the user:",candidateSets[i]._openid);

for(let j = 0; j < GOOD_GIFTS.length; j++){

try{

// send the subsribe message

res = await cloud.callFunction({

// the cloud function name

name:"subscribeGift",

// the parameter:open id, then cloud function will use event.openid to get the parameter

data:{

openid : candidateSets[i]._openid,

type : GOOD_GIFTS[j].type,

title : GOOD_GIFTS[j].title,

notify : GOOD_GIFTS[j].notify,

date : GOOD_GIFTS[j].date,

abstract : GOOD_GIFTS[j].abstract

}

});

}catch(err){

console.log("exception occured",err);

}finally{

console.log("sended the subscribe messege to the user:",candidateSets[i]._openid);

console.log("subscribeGift call result is:",res);

}

} //end of inner for loop

}//end of outer for loop

if( res )

return true;

else

return false;

}

}