Next.js: Error: Cannot find module 'node-sass'

[martpie]

Bug report

Describe the bug

Using any example from the Next.js 9.3 blog article for Scss support does not work (global scss or scss modules: Error: Cannot find module 'node-sass'

details:

./components/Button.module.scss (./node_modules/css-loader/dist/cjs.js??ref--5-oneOf-3-1!./node_modules/postcss-loader/src??__nextjs_postcss!./node_modules/resolve-url-loader??ref--5-oneOf-3-3!./node_modules/sass-loader/dist/cjs.js??ref--5-oneOf-3-4!./components/Button.module.scss)
Error: Cannot find module 'node-sass'
Require stack:
- /Users/pierre/dev/next-sass/node_modules/sass-loader/dist/getDefaultSassImplementation.js
- /Users/pierre/dev/next-sass/node_modules/sass-loader/dist/getSassImplementation.js
- /Users/pierre/dev/next-sass/node_modules/sass-loader/dist/index.js
- /Users/pierre/dev/next-sass/node_modules/sass-loader/dist/cjs.js
- /Users/pierre/dev/next-sass/node_modules/loader-runner/lib/loadLoader.js
- /Users/pierre/dev/next-sass/node_modules/loader-runner/lib/LoaderRunner.js
- /Users/pierre/dev/next-sass/node_modules/webpack/lib/NormalModule.js
- /Users/pierre/dev/next-sass/node_modules/webpack/lib/NormalModuleFactory.js
- /Users/pierre/dev/next-sass/node_modules/webpack/lib/Compiler.js
- /Users/pierre/dev/next-sass/node_modules/webpack/lib/webpack.js
- /Users/pierre/dev/next-sass/node_modules/next/dist/server/hot-reloader.js
- /Users/pierre/dev/next-sass/node_modules/next/dist/server/next-dev-server.js
- /Users/pierre/dev/next-sass/node_modules/next/dist/server/next.js
- /Users/pierre/dev/next-sass/node_modules/next/dist/server/lib/start-server.js
- /Users/pierre/dev/next-sass/node_modules/next/dist/cli/next-dev.js
- /Users/pierre/dev/next-sass/node_modules/next/dist/bin/next

To Reproduce

1. minimal Next.js setup
2. Follow the instructions to add Global Sass or Sass module https://nextjs.org/blog/next-9-3#built-in-sass-support-for-global-stylesheets
3. npm run dev
4. go to the corresponding page

Expected behavior

A clear and concise description of what you expected to happen.

Screenshots

System information

• OS: macOS Catalina
• Browser (if applies) n/a
• Version of Next.js: 9.3.0
• Node.js: 12 & 13 (did not test with others)

Additional context

n/a

[martpie]

Ok, so I fooled myself: the doc explains well to npm install sass manually, but it was not mentioned the blog article. Maybe a clearer warning would be welcome 👍

[r3wt]

the docs:

Next.js has built in sass support

the reality:

Error: Cannot find module 'sass'