Thanks for contributing!
If you're about to report an issue - please first check if it's already been reported in the issues page.
Also check to see if the latest versions of eslint/babel-eslint still produce the issue.
Also check out the Known Issues section of the README.
If you are having issues with JSX you might want to check out eslint-plugin-react. If there's an issue with new experimental syntax you might need to report that in eslint-plugin-babel instead.