Errors thrown inside of queue "completed" handler result in "Missing lock" errors

Created by: sysrun

This one gave me hours of pain...

Description

If an error is throw inside the queue "completed" handler, the queues "error" event will be triggered with "Error: Missing lock for job failed" and errorMessage "Error processing job".

Minimal, Working Test code to reproduce the issue.

After the second iteration the described error will be triggered

const bull = require('bull');

const queue = bull('testqueue', 'redis://localhost:6380');

queue.process(async (job) => {
  console.log('>> processing', job.id);
  return Promise.resolve(true);
});

queue.on('completed', (job, result) => {
  console.log('>>> completed', job.id);
  if (job.data.counter >= 2) {
    console.log('>>> counter >= 2, throwing inside "completed" handler');
    throw Error();
  }
});

queue.on('error', (error, errorMessage) => {
  console.error('error', error);
  console.error('errorMessage', errorMessage);
});

let counter = 0;
setInterval(() => {
  const job = queue.add({counter: counter++});
  console.log('> added job', job.id);
}, 1000);

Bull version

4.1.0