Error: Module did not self-register.

[bdotsamir]

What is wrong?

When training network within a worker thread, the thread fails to start and throws Error: Module did not self-register.

Where does it happen?

On Worker thread initialization, node.js v10.19.0 - LTS, KDE Neon (linux) 5.18, base Ubuntu 18.04

How do we replicate the issue?

Require brain.js in the main thread OR worker thread, it seems.
init.js - Main thread

/* eslint-disable */
const brain = require('brain.js'); // NOTE - If you comment this line out, it continues as normal.

const worker = require('worker_threads');
if(!worker.isMainThread) {
  console.error('Called from main thread. Illegal. Exiting...');
  process.exit(1);
} else {
  
  trainBrain()
    .then(console.log)
    .catch(console.error);

}

function trainBrain() {
  return new Promise((resolve, reject) => {
    const child = new worker.Worker('./worker.js', {
      workerData: {
        foo: 'bar',
        num: 1
      }
    });

    child.on('online', () => console.log('Worker online'));
    child.on('message', resolve);
    child.on('error', reject);
  });
}

worker.js - Worker thread

/* eslint-disable */
const worker = require('worker_threads');
const brain = require('brain.js');  // NOTE - If you comment this line out, it continues as normal.

if(worker.isMainThread) {
  console.error('Worker file called at main thread. Illegal. Exiting...');
  process.exit(1);
}

const { workerData } = worker;
const { foo, num } = workerData;

worker.parentPort.postMessage({ foo, num });

How important is this (1-5)?

2?

Expected behavior (i.e. solution)

In init.js OR worker.js, comment out the brain require statement. Somehow, removing the brain.js require seems to fix the issue.

Other Comments

If you're not already aware, worker_threads in node v10.x is an experimental feature, hidden behind the --experimental_worker flag. If you want to enable it, run the command as follows: node --experimental_worker init.js.
https://nodejs.org/dist/latest-v10.x/docs/api/worker_threads.html

First try is without the brain require commented out. Second try is with the brain require commented out.

[mubaidr]

This is node issue as being discussed here: nodejs/node#21481

In the mean time you could use child_process forks