react-map-gl: uncaught ReferenceError: _typeof is not defined

Question

Trying to work with react-map-gl but can't get the simplest lib example to work. As soon as I try to render the map I get this weird error in console I'm unable to understand:

Uncaught ReferenceError: _typeof is not defined
    at mr (blob:http://localhos…6-19b5d5c80288:4993)
    at blob:http://localhos…6-19b5d5c80288:6740
    at new Fn (blob:http://localhos…6-19b5d5c80288:6757)
    at new Jn (blob:http://localhos…6-19b5d5c80288:7040)
    at blob:http://localhos…6-19b5d5c80288:8992
    at blob:http://localhos…-19b5d5c80288:14153

Sometimes it changes to this:

Uncaught ReferenceError: _typeof is not defined
    at mr (0bcc60f9-25f2-4a56-8906-ebd57645a06c:4993)
    at 0bcc60f9-25f2-4a56-8906-ebd57645a06c:6740
    at new Fn (0bcc60f9-25f2-4a56-8906-ebd57645a06c:6757)
    at new Jn (0bcc60f9-25f2-4a56-8906-ebd57645a06c:7040)
    at 0bcc60f9-25f2-4a56-8906-ebd57645a06c:8992
    at 0bcc60f9-25f2-4a56-8906-ebd57645a06c:14153

The map frame with mapbox logo renders but nothing else.

I'm on Rails 6 with those packages:

"dependencies": {
  "@babel/preset-react": "^7.0.0",
  "@rails/actioncable": "^6.0.0-alpha",
  "@rails/activestorage": "^6.0.0-alpha",
  "@rails/ujs": "^6.0.0-alpha",
  "@rails/webpacker": "^4.0.7",
  "babel-plugin-transform-react-remove-prop-types": "^0.4.24",
  "prop-types": "^15.7.2",
  "react": "^16.9.0",
  "react-dom": "^16.9.0",
  "react-map-gl": "^5.0.10"
}

My code :

import React, { Component } from 'react';
import ReactMapGL from 'react-map-gl';
import 'mapbox-gl/dist/mapbox-gl.css';

class Map extends Component {
  state = {
    viewport: {
      latitude: 20.827873989993776,
      longitude: -73.86145304236818,
      zoom: 3,
    },
  };

  render() {
    return (
      <ReactMapGL
        mapboxApiAccessToken={[TOKEN]}
        {...this.state.viewport}
        onViewportChange={viewport => this.setState({ viewport })}
      />
    );
  }
}

export default Map;

Googled the error the whole afternoon but found nothing.

Answer 1

From the related mapbox-gl issue commented by @JakeWorth I was able to find the solution from a well documented PR referenced in it: https://github.com/lewagon/rails-templates/pull/81

Adding the following line to config/webpack/environment.js prevents Babel from transpiling packages in node_modules which was the cause of my issue.

environment.loaders.delete('nodeModules');