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.**
entry,
  externals,
  updateBabelOptions,
  filename,
  bundleType,
  globalName,
  moduleType,
  modulesToStub,
  featureFlags
) {
  const findAndRecordErrorCodes = extractErrorCodes(errorCodeOpts);
  const shims = Modules.getShims(bundleType, entry, featureFlags);
  const isProduction = isProductionBundleType(bundleType);
  const isInGlobalScope = bundleType === UMD_DEV || bundleType === UMD_PROD;
  const isFBBundle = bundleType === FB_DEV || bundleType === FB_PROD;
  const isRNBundle = bundleType === RN_DEV || bundleType === RN_PROD;
  const shouldStayReadable = isFBBundle || isRNBundle;
  return [
    
    shouldExtractErrors && {
      transform(source) {