Version

3.0.0-rc.3

Reproduction link

https://codepen.io/anon/pen/zaXgNz

Steps to reproduce

Setup vue-cli , and use the setup of vue.config.js from the link above.

What is expected?

To have dist/assets/app.css

What is actually happening?

Without specifying the assets folder manually in the filename it ignores the assetsDir option.