https://github.com/facebook/create-react-app/issues/4492 https://github.com/facebook/create-react-app/pull/4077#issuecomment-389270627 - [concatenateModules](https://github.com/webpack/webpack/blob/master/lib/WebpackOptionsDefaulter.js#L214) option is on by default in production - import in [SvgComponent](https://github.com/facebook/create-react-app/blob/next/packages/react-scripts/fixtures/kitchensink/src/features/webpack/SvgComponent.js) produces [ConcatenatedModule](https://github.com/webpack/webpack/blob/master/lib/optimize/ConcatenatedModule.js#L254) (rather than a [NormalModule](https://github.com/webpack/webpack/blob/master/lib/NormalModule.js)). - ConcatenatedModule doesn't have userRequest field for [webpack-manifest-plugin](https://github.com/danethurber/webpack-manifest-plugin/blob/master/lib/plugin.js#L45), which crashes.
react/create-react-app#4492
react/create-react-app#4077 (comment)