Unable find out where an error occurs exactly -- no stack trace

I have a simple node-js application. After I do an ajax request, an error occurs:

events.js:163
      throw er; // Unhandled 'error' event
      ^

Error: Connection terminated
    at Connection.<anonymous> (/home/user123/my_app123/node_modules/pg/lib/client.js:199:29)
    at Object.onceWrapper (events.js:293:19)
    at emitNone (events.js:91:20)
    at Connection.emit (events.js:188:7)
    at Socket.<anonymous> (/home/user123/my_app123/node_modules/pg/lib/connection.js:141:10)
    at emitNone (events.js:91:20)
    at Socket.emit (events.js:188:7)
    at endReadableNT (_stream_readable.js:974:12)
    at _combinedTickCallback (internal/process/next_tick.js:80:11)
    at process._tickCallback (internal/process/next_tick.js:104:9)

There's no additional information, no stacktrace. Where exactly it occured in the source code? I don't know.

Even console.log doesn't help:

app.post("/my_url123", (req, res) => {

  const client = new pg.Client(.....);
  client.connect((err) => {
    if (err) {
      console.log(err, err.stack.split("\n")); //no difference
      throw err;
    }

via Dorion