Can't start stream query because query.start() throws error

Hi there! I'm trying to stream results from an sql select, but when I call query.start() it throws the following error:

2023-10-17T00:55:03.668Z	cfca73dc-e40f-46f7-bc83-059c4ff1c6d6	ERROR	Handler error: Cannot read properties of undefined (reading 'config'):  {
  aws_request_id: 'cfca73dc-e40f-46f7-bc83-059c4ff1c6d6',
  function_name: 'test_function',
  stackTrace: "TypeError: Cannot read properties of undefined (reading 'config')\n" +
    '    at Query.start (/var/task/handler.js:64172:25)\n' +
    '    at handler (/var/task/handler.js:69581:9)\n' +
    '    at async Runtime.handler (/var/task/handler.js:69219:12)',

Sorry for the bundle stack trace, it's in a lambda function handler. This is when running locally. Here is the code that calls it:

  const query = connection.query(sql, values);
  const stream = query.stream();
  stream
    .on('error', function (err) {
      console.log('err:', err);
    })
    .on('result', function (row) {
      console.log('row:', row);
    })
    .on('fields', (fields) => {
      console.log('fields:', fields);
    })
    .on('end', function () {
      console.log('ENDED');
    });
  query.start();

I do see all the column definitions in the fields handler. Tracking down the offending code in the bundle, it appears to be the first line in the start() function:

      /* eslint no-unused-vars: ["error", { "argsIgnorePattern": "^_" }] */
      start(_packet, connection2) {
        if (connection2.config.debug) {    <==== HERE =================================
          console.log("        Sending query command: %s", this.sql);
        }
        this._connection = connection2;
        this.options = Object.assign({}, connection2.config, this._queryOptions);
        this._setTimeout();
        const cmdPacket = new Packets.Query(
          this.sql,
          connection2.config.charsetNumber
        );
        connection2.writePacket(cmdPacket.toPacket(1));
        return Query.prototype.resultsetHeader;
      }
      done() {
        this._unpipeStream();
        if (this.timeout && !this.queryTimeout) {
          return null;
        }

I wonder if I'm doing something wrong? Any thoughts?
Thanks in advance! :)

Start at the Query.start entry point shown in the report and trace how the stream() call invokes it. Reproduce the provided connection.query(...).stream() sequence, then compare it with the project's documented streaming usage or relevant tests. Done means the query starts without an undefined connection configuration and streamed rows complete successfully, or the issue is clarified as incorrect usage.