This is a minimal reproduction of a bug with @unocss/webpack and Webpack persistent caching.

1. Install dependencies with yarn
2. Perform a production build with yarn build
3. Observe the built dist/main.css or view the rendered content with yarn serve. unocss classes should be correctly generated and applied properly.
4. Perform another production build (should be faster due to persistent caching)
5. Observe the built CSS. It should contain normal imported CSS rules but (incorrectly) not any unocss classes.