Final build is broken when using pnpm

[Nick-Mazuk]

Issue

I just recently switched from using npm to pnpm workspaces in a monorepo with a Next.js project. However, since the switch, the final builds are broken.

• works perfectly in development
• no errors during the build
• same results when building on my local machine

When you visit the homepage of the website, the following error message appears in the "Functions" tab on the Vercel dashboard.

[GET] /
15:54:17:81
2021-02-15T23:54:17.925Z	1dd68a87-f22c-4e8b-a12e-979eeaff35b4	ERROR	Unhandled error during request: Error: Cannot find module '@hapi/accept'
Require stack:
- /var/task/website/.next/serverless/pages/index.js
- /var/task/website/now__launcher.js
- /var/runtime/UserFunction.js
- /var/runtime/index.js
    at Function.Module._resolveFilename (internal/modules/cjs/loader.js:815:15)
    at Function.Module._load (internal/modules/cjs/loader.js:667:27)
    at Module.require (internal/modules/cjs/loader.js:887:19)
    at require (internal/modules/cjs/helpers.js:74:18)
    at Object.Qlez (/var/task/website/.next/serverless/pages/index.js:4757:18)
    at __webpack_require__ (/var/task/website/.next/serverless/pages/index.js:31:31)
    at Object.0bak (/var/task/website/.next/serverless/pages/index.js:288:482)
    at __webpack_require__ (/var/task/website/.next/serverless/pages/index.js:31:31)
    at Object.synw (/var/task/website/.next/serverless/pages/index.js:10746:196)
    at __webpack_require__ (/var/task/website/.next/serverless/pages/index.js:31:31) {
  code: 'MODULE_NOT_FOUND',
  requireStack: [
    '/var/task/website/.next/serverless/pages/index.js',
    '/var/task/website/now__launcher.js',
    '/var/runtime/UserFunction.js',
    '/var/runtime/index.js'
  ]
}
2021-02-15T23:54:17.935Z	1dd68a87-f22c-4e8b-a12e-979eeaff35b4	ERROR	Uncaught Exception 	{"errorType":"Error","errorMessage":"Cannot find module '@hapi/accept'\nRequire stack:\n- /var/task/website/.next/serverless/pages/index.js\n- /var/task/website/now__launcher.js\n- /var/runtime/UserFunction.js\n- /var/runtime/index.js","code":"MODULE_NOT_FOUND","requireStack":["/var/task/website/.next/serverless/pages/index.js","/var/task/website/now__launcher.js","/var/runtime/UserFunction.js","/var/runtime/index.js"],"stack":["Error: Cannot find module '@hapi/accept'","Require stack:","- /var/task/website/.next/serverless/pages/index.js","- /var/task/website/now__launcher.js","- /var/runtime/UserFunction.js","- /var/runtime/index.js","    at Function.Module._resolveFilename (internal/modules/cjs/loader.js:815:15)","    at Function.Module._load (internal/modules/cjs/loader.js:667:27)","    at Module.require (internal/modules/cjs/loader.js:887:19)","    at require (internal/modules/cjs/helpers.js:74:18)","    at Object.Qlez (/var/task/website/.next/serverless/pages/index.js:4757:18)","    at __webpack_require__ (/var/task/website/.next/serverless/pages/index.js:31:31)","    at Object.0bak (/var/task/website/.next/serverless/pages/index.js:288:482)","    at __webpack_require__ (/var/task/website/.next/serverless/pages/index.js:31:31)","    at Object.synw (/var/task/website/.next/serverless/pages/index.js:10746:196)","    at __webpack_require__ (/var/task/website/.next/serverless/pages/index.js:31:31)"]}
Unknown application error occurred

I can confirm that the package @hapi/accept is in the pnpm-lock.yaml. Next.js is the only package that requires @hapi/accept.

Debug steps

• Perhaps @hapi/accept is not in the pnpm-lock.yaml, it is
• Confirmed all the node_modules are loaded, even though this is a project in a pnpm workspace
• Confirmed this isn't a dev/production dependency issue. I moved all dependencies to production dependencies to ensure they are bundled. That did not help.
• pnpm is strict about making sure your dependencies are declared in package.json (and all of your dependency's dependencies). So I created a build on my local machine with everything installed. The build has the same issues (and still works in development)
• There are several other threads about pnpm. From what I can tell, this seems to be a new issue Previous reports are resolved, or deal with build on Vercel. And I get the same errors on a local build. Not working with PNPM #16471 Resolve to real path before checking for path inequality #17279 Add pnpm integration test #17882 Support for pnpm as an alternative to Yarn vercel#3896 (reply in thread) Use resolveRequest to compare symlinks, rather than fs.realpathSync (fix pnpm on Vercel) #20949

Metadata

next: 10.0.7

[damiangreen]

--shamefully-hoist not working for me.. is there another solution?

[ShukantPal]

Note that I had to delete an existing .next directory after installing with --shamefully-hoist to make the production build pass.