Getting "Cannot find module 'next/dist/next-server/server/node-polyfill-fetch'" when deployed

[olaven]

Hi! Thanks for maintaining this project 😄

My Next.js-app throws the following error when I am using nextjs auth0:
2020-06-21T12:31:15.731Z undefined ERROR Uncaught Exception {"errorType":"Runtime.ImportModuleError","errorMessage":"Error: Cannot find module 'next/dist/next-server/server/node-polyfill-fetch'\nRequire stack:\n- /var/task/.next/serverless/pages/api/auth/me.js\n- /var/task/now__launcher.js\n- /var/runtime/UserFunction.js\n- /var/runtime/index.js","stack":["Runtime.ImportModuleError: Error: Cannot find module 'next/dist/next-server/server/node-polyfill-fetch'","Require stack:","- /var/task/.next/serverless/pages/api/auth/me.js","- /var/task/now__launcher.js","- /var/runtime/UserFunction.js","- /var/runtime/index.js"," at _loadUserApp (/var/runtime/UserFunction.js:100:13)"," at Object.module.exports.load (/var/runtime/UserFunction.js:140:17)"," at Object.<anonymous> (/var/runtime/index.js:43:30)"," at Module._compile (internal/modules/cjs/loader.js:1133:30)"," at Object.Module._extensions..js (internal/modules/cjs/loader.js:1153:10)"," at Module.load (internal/modules/cjs/loader.js:977:32)"," at Function.Module._load (internal/modules/cjs/loader.js:877:14)"," at Function.executeUserEntryPoint [as runMain] (internal/modules/run_main.js:74:12)"," at internal/main/run_main_module.js:18:47"]}Unknown application error occurredRuntime.ImportModuleError

Everything works fine when running locally with dev and build/start.
I had this issue last week. Then it (confusingly) disappeared when I added .github and .vscode to .vercelignore. However, it reappeared a couple days ago.

I'm using next 9.4.4, but I have tested with 9.3 as well.
Furthermore, I'm running node 12, both locally and on vercel (through engines in package.json)

Has anyone experienced something similar? Any help is very much appreciated!

[paleite]

There's another issue regarding this here: #16667

[olaven]

Thanks for providing the link! 😄