Unable to cancel promise (Node.js)

[fider-apptimia]

1. What version of bluebird is the issue happening on?
   "bluebird": "^3.7.2",
   "@types/bluebird": "^3.5.33",

2. What platform and version?
   Using ts-node version 8.10.2, typescript version 3.9.5
   node v12.18.4

3. Did this issue happen with earlier version of bluebird?
   No idea.

4. Reproduce

import P = require('bluebird');

P.config({
  cancellation: true,
});

async function go() {
  setTimeout(() => {}, 5000); // keep alive

  console.log('start');

  const p = new P((resolve: any, reject: any, onCancel: any) => {
    const to = setTimeout(() => resolve(), 2000);

    onCancel(() => {
      console.log('onCancel called');
      clearTimeout(to);
      reject(new Error('cancel')); // no error throwed. With resolve() in this place it also hangs on await
    });
  });

  setTimeout(() => p.cancel(), 1000);

  await p;

  console.log('end');
}

go();

Actual output:

start
onCancel called

Expected output:

start
onCancel called
end

[benjamingr]

Promise cancellation probably just doesn't work with async/await well?

It makes sense with third-state cancellation that end isn't called.

[bergus]

You're rejecting the promise. Why would you expect end to still be called?

[fider-apptimia]

@bergus it is not working neither with resolve nor with reject - it just hangs on await in both cases.
(btw. reject without try/catch should throw and here nothing happens)