node 20.1.0 --loader can not longer listening process events

[joacub]

Version

20.1.0

Platform

any

Subsystem

any

What steps will reproduce the bug?

 const runProcess = spawn(
    process.execPath,
    [
      '--require',
      require.resolve('./preflight.cjs'),

      '--loader',
      pathToFileURL(require.resolve('./loader.js')).toString(),

      '--loader',
      '@wsy/hot-esm',

      ...argv,
    ],
    {
      stdio,
      env: environment,
    },);

runProcess.send({fileChanged: true, ...rest});

now loaders can not hear process events and some implementations like hot reload in dev mode can not be done (at least not with only one master watcher that propagates to child loaders in order to revalidate)

How often does it reproduce? Is there a required condition?

No response

What is the expected behavior? Why is that the expected behavior?

No response

What do you see instead?

no response

Additional information

No response

[targos]

Since Node.js 20, the loaders are not executed on the main application thread anymore, but on a separate worker thread.
You can establish a communication channel between the main thread and the loaders thread using the globalPreload hook: https://nodejs.org/dist/latest-v20.x/docs/api/esm.html#globalpreload

[aduh95]

Working as expected, closing. If you think the fox can be improved, please open a PR or comment on this issue.