### Version 15.7.1 ### Reproduction link [https://github.com/Lyrkan/repro-vue-loader-webpack5](https://github.com/Lyrkan/repro-vue-loader-webpack5) ### Steps to reproduce * Create a project that uses Webpack 5 and vue-loader 15.7.1 * Try to run Webpack ### What is expected? No error ### What is actually happening? Error: Cannot find module 'webpack/lib/RuleSet' --- Hi there, Webpack 5 (that just got into beta) removed the `RuleSet` class that is [currently used by the `vue-loader` plugin](https://github.com/vuejs/vue-loader/blob/e1c11cf87dfab6e57a17b0707686f389de04dec2/lib/plugin.js#L2) in the following PR: https://github.com/webpack/webpack/pull/9138 This makes any attempt to use the plugin fail with a "Cannot find module webpack/lib/RuleSet" error. <!-- generated by vue-issues. DO NOT REMOVE -->