Version

3.0.0-beta.6

Reproduction link

https://github.com/davidwallacejackson/vue-cli-css-import-repro

Steps to reproduce

1. npm install
2. npx vue-cli-service e2e

What is expected?

The automatically-generated E2E tests should pass.

What is actually happening?

The E2E tests time out. In the browser console, there's an error: "extract-text-webpack-plugin" loader is used without the corresponding plugin

vue.config.js is configured to prebuild '@/module-importing-css' into a DLL, which is then referenced from main when it imports './module-importing-css'. If you comment out that line in the config, the tests run correctly.

There's another issue about people encountering this same error (#997) but the context seems very different (they're using Windows and they're not running e2e tests), so I wasn't sure the error was actually caused by the same bug in both cases.