When updating Next.js v10.1.13 to webpack5, getting warnings Can't resolve 'fsevents' in chokidar

Question

npm install next react react-dom And running Node.js v12

Created most simple pages/index.tsx

export default function PageHome(props) {
  return <>Hello World!</>
}

(I also had TypeScript configured as per Next.js instructions but not sure if that's making a difference.)

C:\GitHub\reproduce-nextjs-webpack5-error>npm run dev
...
event - compiled successfully
<w> [webpack.cache.PackFileCacheStrategy] Caching failed for pack: Error: Can't resolve 'fsevents' in 'C:\GitHub\reproduce-nextjs-webpack5-error\node_modules\next\node_modules\chokidar'
<w> while resolving 'fsevents' in C:\GitHub\reproduce-nextjs-webpack5-error\node_modules\next\node_modules\chokidar to a directory
<w> [webpack.cache.PackFileCacheStrategy] Caching failed for pack: Error: Can't resolve 'fsevents' in 'C:\GitHub\reproduce-nextjs-webpack5-error\node_modules\next\node_modules\chokidar'
<w> while resolving 'fsevents' in C:\GitHub\reproduce-nextjs-webpack5-error\node_modules\next\node_modules\chokidar to a directory

Self-answered solution below for future readers.

Answer 1

1. Upgrade Node.js

2. Delete package-lock.json and node_modules

3. Run npm install again

4. It works

   • Apparently something doesn't install when you run with an older Node.js version.

   • My package.json looked like

     {
       "scripts": {
         "dev": "next dev",
         "build": "next build",
         "start": "next start"
       },
       "dependencies": {
         "next": "^10.1.3",
         "react": "^17.0.2",
         "react-dom": "^17.0.2"
       },
       "devDependencies": {
         "@types/react": "^17.0.3",
         "typescript": "^4.2.4"
       }
     }
     

   • The same package.json will install slightly differently switching from Node.js v12 to Node.js v15 as I just observed. This is why you have to complete not just step 1, but also steps 2 & 3.

Before:

C:\GitHub\reproduce-nextjs-webpack5-error>node --version
v12.4.0

C:\GitHub\reproduce-nextjs-webpack5-error>npm run dev

> @ dev C:\GitHub\reproduce-nextjs-webpack5-error
> next dev

ready - started server on 0.0.0.0:3000, url: http://localhost:3000
info  - Using webpack 5. Reason: future.webpack5 option enabled https://nextjs.org/docs/messages/webpack5
event - compiled successfully
<w> [webpack.cache.PackFileCacheStrategy] Caching failed for pack: Error: Can't resolve 'fsevents' in 'C:\GitHub\reproduce-nextjs-webpack5-error\node_modules\next\node_modules\chokidar'
<w> while resolving 'fsevents' in C:\GitHub\reproduce-nextjs-webpack5-error\node_modules\next\node_modules\chokidar to a directory

After:

C:\GitHub\reproduce-nextjs-webpack5-error>node --version
v15.14.0

C:\GitHub\reproduce-nextjs-webpack5-error>npm run dev

> dev
> next dev

ready - started server on 0.0.0.0:3000, url: http://localhost:3000
info  - Using webpack 5. Reason: future.webpack5 option enabled https://nextjs.org/docs/messages/webpack5
event - compiled successfully
event - build page: /
wait  - compiling...
event - compiled successfully

Yay! No warnings!

While there are comments below about future changes in nextjs@canary, the above examples worked for me with versions listed.