An example of [email protected] outputting incorrect default modules.

build.js

module.exports =(n) {
  return n * n;
}

index.js

export default function square(n) {
  return n * n;
}

package.json

{
  "name": "bundt-demo",
  "version": "0.0.0",
  "description": "",
  "main": "build.js",
  "scripts": {
    "build": "bundt index.js"
  },
  "keywords": [],
  "devDependencies": {
    "bundt": "^1.1.3"
  }
}