Next.js 13: Build failure when enabling appDir and using Yarn PnP

[shun-shobon]

Verify canary release

• I verified that the issue exists in the latest Next.js canary release

Provide environment information

Operating System:
  Platform: darwin
  Arch: x64
  Version: Darwin Kernel Version 21.6.0: Mon Aug 22 20:17:10 PDT 2022; root:xnu-8020.140.49~2/RELEASE_X86_64
Binaries:
  Node: 18.12.0
  npm: 8.19.2
  Yarn: 3.2.4
  pnpm: N/A
Relevant packages:
  next: 13.0.2-canary.2
  eslint-config-next: N/A
  react: 18.2.0
  react-dom: 18.2.0

What browser are you using? (if relevant)

No response

How are you deploying your application? (if relevant)

No response

Describe the Bug

When using Yarn PnP to manage packages, running next bulid with appDir enabled will fail to build.
The build log is:

warn  - You have enabled experimental feature (appDir) in next.config.js.
warn  - Experimental features are not covered by semver, and may cause unexpected or broken application behavior. Use at your own risk.
info  - Thank you for testing `appDir` please leave your feedback at https://nextjs.link/app-feedback

warn  - `enableUndici` option is unnecessary in Node.js v18.0.0 or greater.

> Build error occurred
Error: EROFS: read-only filesystem, open '/node_modules/next/dist/server/initialize-require-hook.js'
    at makeError$1 (/Users/shun_shobon/tmp/my-app/.pnp.cjs:958:24)
    at EROFS (/Users/shun_shobon/tmp/my-app/.pnp.cjs:985:10)
    at ZipFS.prepareWriteFile (/Users/shun_shobon/tmp/my-app/.pnp.cjs:2820:13)
    at ZipFS.writeFilePromise (/Users/shun_shobon/tmp/my-app/.pnp.cjs:2791:55)
    at /Users/shun_shobon/tmp/my-app/.pnp.cjs:3912:26
    at /Users/shun_shobon/tmp/my-app/.pnp.cjs:4136:81
    at ZipOpenFS.getZipPromise (/Users/shun_shobon/tmp/my-app/.pnp.cjs:4243:22)
    at ZipOpenFS.makeCallPromise (/Users/shun_shobon/tmp/my-app/.pnp.cjs:4136:23)
    at ZipOpenFS.writeFilePromise (/Users/shun_shobon/tmp/my-app/.pnp.cjs:3909:23)
    at VirtualFS.writeFilePromise (/Users/shun_shobon/tmp/my-app/.pnp.cjs:3219:24) {
  code: 'EROFS'
}

Looking at the error log, it appears that the attempt to write in next/dist/server/initialize-require-hook.js is failing:

next.js/packages/next/build/index.ts

Lines 317 to 324 in ef73798

	await promises
	.writeFile(
	initialRequireHookFilePath,
	content.replace(
	/isPrebundled = (true|false)/,
	`isPrebundled = ${isAppDirEnabled}`
	)
	)

Expected Behavior

No error logs are displayed and the build succeeds.

Link to reproduction

https://github.com/shun-shobon/nextjs-13-yarn-berry-build-reproduction

To Reproduce

• clone this repo
• run yarn to install dependencies
• run yarn build
• an error log is output and the build fails

_NEXT-1378

[twavv]

I just ran into this. A temporary workaround is to yarn unplug next.

[nastynaz]

I spent hours trying to figure this out. Bump.

[Revolt9k]

Same problem

[madjam002]

This is also a problem when running ‘next build’ where node_modules is on a read only file system as is the case with some build systems.

[cyrilwanner]

We are also facing this issue with Bazel (rules_js & pnpm) when trying to enable the appDir feature.
Modifying files within node_modules might work for simple setups, but can cause a lot of issues with more complex and restrictive build systems where node_modules is on a read only file system (for example to avoid any side effects when sharing dependencies between build agents and for guaranteeing hermetic builds).

It looks like this was introduced in #41687

@huozhi @ijjk would it be possible to maybe move this file to the .next output folder or avoid writing it in node_modules in another way, e.g. by checking if the appDir feature is enabled differently?
I am also happy to contribute if there is a common agreement on how this should be fixed.

[samwightt]

Bump, this really needs attention. Huge blocker for anyone using yarn 2.

[ranisalt]

Not a good idea for a dependency to modify its own source code when ran... Just generate this file elsewhere

[power-f-GOD]

I just faced this issue with pnpm as well.😕 Any concrete solutions yet?

[codebycarlos]

Just came across this as well, huge problem for anyone using Yarn's PnP.