Why all promises ever performed are reported

[imrefazekas]

I'm having hard time with this lib.
It reports all promises the running app ever performed.

hashtab PROMISE
/.../node_modules/mongodb/lib/utils.js:432 - return new Promise(function(resolve, reject) {

All promises performed by any libraries. Mongodb driver or actually anything.
Even is the app shuts down clearly, it says:
There are 10272 handle(s) keeping the process running

Is there a way to learn why async / await promises give such a headache to this lib?

[mafintosh]

fixed by #37