Error running parcel serve from javascript api

[imakeinterfaces]

Hello all. I am trying to run parcel 2 from the Parcel API using code similar to what I found here: https://v2.parceljs.org/features/parcel-api/

Here is what my code looks like:

const path = require('path');
const Parcel = require('@parcel/core').default;

(async () => {
  const bundler = new Parcel({
    defaultConfig: require.resolve('@parcel/config-default'),
    entries: path.join(__dirname, 'index.pug'),
    serve: {
      port: 8080,
      distDir:'../dist',  // This is in the main config options in the example but here in the docs
      host: 'http://localhost',
      https: false,
    },
    distDir: '../dist',
    defaultEngines: {
      browsers: ['last 1 Chrome version'],
      node: '14',
    },
    mode: 'development',
    patchConsole: false,
  });

  await bundler.run();
})();

In my package.json, npm start is simply node src/build.js

My problem is that if I run like this, the build completes but then gives me the error @parcel/reporter-dev-server: Could not send success event to devserver because it does not exist.

If i remove the serve object from the config, the app will build but will exit the command not run parcel serve. The error is the same as the one in this discussion #4968 except that the build stops in my case when it reaches the error.

I'm currently running the 439 nightly as the newer versions fail to build my app for other reasons. 439 works fine as long as i use the CLI.

The only transformer i'm currently using is the graphql transformer:
"@parcel/transformer-graphql": "^2.0.0-nightly.441"
"parcel": "^2.0.0-nightly.439"