Assertion error thrown in internal/child_process.js on Linux

[Trott]

On Linux using current master, this code:

'use strict';
const common = require('../common');
const net = require('net');
const cluster = require('cluster');
cluster.schedulingPolicy = cluster.SCHED_NONE;

if (cluster.isMaster) {
  var worker1, worker2;

  worker1 = cluster.fork();
  worker1.on('message', common.mustCall(function() {
    worker2 = cluster.fork();
    worker1.disconnect();
    worker2.disconnect();
  }));

  return;
}

var server = net.createServer();

server.listen(common.PORT, function() {
  process.send('listening');
});

...results in this output...

assert.js:90
  throw new assert.AssertionError({
  ^
AssertionError: null == true
    at process.target._send (internal/child_process.js:520:5)
    at process.<anonymous> (internal/child_process.js:486:12)
    at emitTwo (events.js:94:20)
    at process.emit (events.js:174:7)
    at handleMessage (internal/child_process.js:687:10)
    at Pipe.channel.onread (internal/child_process.js:439:11)

(The script still exits with a successful return code so the script above is not sufficient for testing on the Node CI infrastructure.)

[cjihrig]

Can you put the worker2.disconnect(); inside of a worker2.on('online', ...)

[Trott]

@cjihrig Is the idea to fix an error in the script? The issue is that the error being thrown is an AssertionError, so the script is creating a condition in Node core that the author (who put the assertion there) believed and expected to be impossible to create.

[Trott]

@cjihrig And if you were asking to get troubleshooting info: I made the change you suggest and the AssertionError still gets thrown.