Sass Loader Error: Invalid options object. Stylus Loader has been initialized using an options object that does not match the API schema

node.js vue.js npm vue-cli stylus

This is a result of a recent compatibility issue between stylus-loader and vue-cli. It was recently fixed in Vue's dev branch.

The best bet for now is to downgrade stylus-loader to version 3

npm install stylus-loader@3

You can also try upgrading your vue-cli to the latest version:

npm update -g @vue/cli
OR
yarn global upgrade --latest @vue/cli

CodeHunter