I updated an old Next.js app and when I ran npm run dev
I had this error:
error - ./node_modules/next/dist/build/webpack/loaders/css-loader/src/index.js??ruleSet[1].rules[2].oneOf[8].use[1]!./node_modules/next/dist/build/webpack/loaders/postcss-loader/src/index.js??ruleSet[1].rules[2].oneOf[8].use[2]!./styles/globals.css
Error: Your custom PostCSS configuration must export a `plugins` key.
I added a postcss.config.json
file with this content:
{
"plugins": [
]
}
and the app started working again.