Minimal reproduction case for webpack-contrib/extract-text-webpack-plugin#579

Steps to reproduce

1. npm install
2. node_modules/.bin/webpack-dev-server --no-inline
3. Open http://localhost:8080/ in a browser
4. Open the dev tools
5. Notice no errors are logged
6. Open the sources pane or network tab and view main.built.js
7. Notice the entry with module.exports = jQuery;
8. Change public/yesExtract.css (for example, change the background color)
9. Notice the app recompiles with no errors
10. Refresh the page
11. Notice an error is logged to the console
12. Notice main.built.js no longer has an entry with module.exports = jQuery. Requires that were meant to reach that module incorrectly point to another, which is why the above logged call fails.