What does this error mean? With `useBuiltIns` option, required direct setting of `corejs` option

Question

I just started getting this error in my static assets build with parcel.js. It works locally but my build on Heroku is erroring and I'm not sure if it's related.

Answer 1

Getting the same issue. Resolved it by installing core-js as a top level dependency and then adding it as an option to .babelrc

npm install --save core-js@3

Then updated my .babelrc file to include it as an option:

 {
  "presets": [
    [ "@babel/preset-env", {
      "useBuiltIns": "entry",
      "corejs": 3
    }]
  ],
  "plugins": [
    "@babel/plugin-syntax-dynamic-import",
    "@babel/plugin-syntax-import-meta",
    ["@babel/plugin-proposal-class-properties", { "loose": false }],
    "@babel/plugin-proposal-json-strings"
  ]
}

I referenced the docs here to figure it out https://babeljs.io/docs/en/babel-preset-env#usebuiltins