Currently when the build fails (e.g. due to a missing named export), the message is pretty ugly:

<img width="1033" alt="screen shot 2017-11-04 at 13 12 31" src="https://user-images.githubusercontent.com/810438/32405680-d618d2e6-c161-11e7-9b91-e0241c7c3eed.png">

It would be nice to display the relevant line inline with syntax highlighting, sort of like Babel does it. Maybe Babel's `babel-code-frame` could be helpful (not sure).

To reproduce, fail the build by removing some `export` somewhere and run `yarn build`. (Tip: `yarn build core --type=NODE_DEV` is the fastest way to build just `packages/react/*` and that might be enough to reproduce and iterate on the error message.)

The relevant logic for displaying build errors is probably somewhere in `scripts/rollup/build.js`.

**If you'd like to work on this please comment here, so we don't have many people working on the same thing.**
const UMD_PROD = Bundles.bundleTypes.UMD_PROD;
const NODE_DEV = Bundles.bundleTypes.NODE_DEV;
const NODE_PROD = Bundles.bundleTypes.NODE_PROD;
const FB_DEV = Bundles.bundleTypes.FB_DEV;
const FB_PROD = Bundles.bundleTypes.FB_PROD;
const RN_DEV = Bundles.bundleTypes.RN_DEV;
const RN_PROD = Bundles.bundleTypes.RN_PROD;
const requestedBundleTypes = (argv.type || '')
  .split(',')
  .map(type => type.toUpperCase());
const requestedBundleNames = (argv._[0] || '')
  .split(',')
  .map(type => type.toLowerCase());
const syncFbsource = argv['sync-fbsource'];
const syncWww = argv['sync-www'];
const shouldExtractErrors = argv['extract-errors'];
const errorCodeOpts = {
  errorMapFilePath: 'scripts/error-codes/codes.json',
};
const closureOptions = {
  compilationLevel: 'SIMPLE',
  languageIn: 'ECMASCRIPT5_STRICT',
  languageOut: 'ECMASCRIPT5_STRICT',
  env: 'CUSTOM',
  warningLevel: 'QUIET',
  applyInputSourceMaps: false,
  useTypesForOptimization: false,
  processCommonJsModules: false,
};
function getBabelConfig(updateBabelOptions, bundleType, filename) {