Deploying NextJS to Vercel failed - next.js

Question

I am trying to deploy an app to Vercel, and getting this error at build
14:13:58.168 Cloning github.com/ChrisB007/moodflics (Branch: main, Commit: 7a2acfe)
14:13:58.575 Cloning completed: 406.06ms
14:13:58.624 Analyzing source code...
14:13:59.946 Installing build runtime...
14:14:03.139 Build runtime installed: 3.193s
14:14:07.055 Build cache not provided
14:14:08.517 Installing dependencies...
14:14:09.142 npm WARN read-shrinkwrap This version of npm is compatible with lockfileVersion#1, but package-lock.json was generated for lockfileVersion#2. I'll try to do my best with it!
14:14:23.664 npm WARN moodflics#0.1.0 No repository field.
14:14:23.676 npm WARN optional SKIPPING OPTIONAL DEPENDENCY: fsevents#2.3.2 (node_modules/fsevents):
14:14:23.677 npm WARN notsup SKIPPING OPTIONAL DEPENDENCY: Unsupported platform for fsevents#2.3.2: wanted {"os":"darwin","arch":"any"} (current: {"os":"linux","arch":"x64"})
14:14:23.681 added 387 packages from 281 contributors in 14.582s
14:14:23.836 62 packages are looking for funding
14:14:23.836 run `npm fund` for details
14:14:23.861 Detected Next.js version: 10.2.0
14:14:23.864 Running "npm run build"
14:14:24.144 > moodflics#0.1.0 build /vercel/path0
14:14:24.144 > next build
14:14:24.557 warn - React 17.0.1 or newer will be required to leverage all of the upcoming features in Next.js 11. Read more: https://nextjs.org/docs/messages/react-version
14:14:24.912 info - Using webpack 5. Reason: no custom webpack configuration in next.config.js https://nextjs.org/docs/messages/webpack5
14:14:25.052 info - Checking validity of types...
14:14:25.068 Attention: Next.js now collects completely anonymous telemetry regarding usage.
14:14:25.068 This information is used to shape Next.js' roadmap and prioritize features.
14:14:25.068 You can learn more, including how to opt-out if you'd not like to participate in this anonymous program, by visiting the following URL:
14:14:25.068 https://nextjs.org/telemetry
14:14:25.123 info - Creating an optimized production build...
14:14:29.905 Failed to compile.
14:14:29.906 ModuleNotFoundError: Module not found: Error: Can't resolve 'next-auth/client' in '/vercel/path0/pages'
14:14:29.906 > Build error occurred
14:14:29.907 Error: > Build failed because of webpack errors
14:14:29.907 at /vercel/path0/node_modules/next/dist/build/index.js:17:924
14:14:29.907 at async Span.traceAsyncFn (/vercel/path0/node_modules/next/dist/telemetry/trace/trace.js:6:584)
14:14:29.946 npm ERR! code ELIFECYCLE
14:14:29.947 npm ERR! errno 1
14:14:29.951 npm ERR! moodflics#0.1.0 build: `next build`
14:14:29.951 npm ERR! Exit status 1
14:14:29.951 npm ERR!
14:14:29.951 npm ERR! Failed at the moodflics#0.1.0 build script.
14:14:29.951 npm ERR! This is probably not a problem with npm. There is likely additional logging output above.
14:14:29.959 npm ERR! A complete log of this run can be found in:
14:14:29.959 npm ERR! /vercel/.npm/_logs/2021-05-10T18_14_29_952Z-debug.log
14:14:29.972 Error: Command "npm run build" exited with 1
Everything seems to be working fine locally, but when I tried deploying it to Vercel I got the above error message. Can you tell me how to fix it?

Answer 1

Sometimes Vercel acts wired that my codes run locally(npm run dev) but fail after upload. This happens when I use Github automatic deployment, i.e. I directly push to my Github repo then Vercel automatically build and update.
However, using Vercel CLI solved my problem. run vercel for preview then vercel --prod for deployment in production

Answer 2

It can't resolve next-auth/client
ModuleNotFoundError: Module not found: Error: Can't resolve 'next-auth/client' in '/vercel/path0/pages'
Ensure that next-auth is properly installed as a dependency and not a dev dependency. Also upgrade your version of react, it's throwing a warning about it not being 17.01 or higher. If you are using typescript, try module augmentation via the next-auth namespace as indicated in their documentation for typescript namespaces. For example, an #/types/next.d.ts file and an #/types/next-auth.d.ts file for module augmentation.
Locally, I use nextauth as well, and have the following in my #/types/next.d.ts file:
import type { NextComponentType, NextPageContext } from 'next';
import type { Session } from 'next-auth';
import type { Router } from 'next/router';
declare module 'next/app' {
type AppProps<P = Record<string, unknown>> = {
Component: NextComponentType<NextPageContext, any, P>;
router: Router;
__N_SSG?: boolean;
__N_SSP?: boolean;
pageProps: P & {
/** Initial session passed in from getServerSideProps or getInitialProps */
session?: Session;
};
};
}
As for the contents of my #/types/next-auth.d.ts file, it's for a custom headless wordpress auth flow, but you can customize the Session/User interfaces regardless of whether you're using a custom approach or not
import NextAuth, { User } from 'next-auth';
import { JWT } from 'next-auth/jwt';
import { WordpressUserPartialFragment } from '../graphql/generated/graphql';
declare module 'next-auth' {
interface Session extends WordpressUserPartialFragment {
response: {
accessToken: string;
id: string;
avatar: {
url: string;
};
description: string | null;
slug: string;
username: string;
email: string;
firstName: string;
lastName: string;
token_exp: string;
refresh_token: string;
locale: string;
};
}
}

Answer 3

Delete node_modules and run yarn install.
Then do yarn build.
If you use npm then do npm i and npm run build instead of yarn install and yarn build.
Then deploy

Answer 4

Check .vercelignore file for folders/files you are missing.
In my case, I have included folder and forgot.
Also double check what source files got synced to vercel, under project deployments, source tab.