Steps to reproduce

Clone and run npm i

Run npm start

See the build error:

🚨  /Users/oliverjam/Web/parcel-babel-error/index.js:5:4: /Users/oliverjam/  3 | rcel-babel-error/index.js: Missing class properties transform.
  4 | class App extends React.Component {
> 5 |     state = {}
    |     ^
  6 |     render() {
  7 |         return <h1>Hello</h1>
  8 |     }