Link to the code that reproduces this issue

https://github.com/TheodoreRed/reproduce-next-15.1.7-bug

To Reproduce

1. Clone the repo and install dependencies:

   npm install

2. Start the dev server:

   npm run dev

3. Make a GET request to:

   http://localhost:3000/api/dummy/982h89f9082h3/something
   

4. Observe the error in the terminal:

   ⨯ [Error: ENOENT: no such file or directory, open '/path/to/project/.next/server/app/api/dummy/[signal_id]/something/[__metadata_id__]/route/app-paths-manifest.json'] {
     errno: -2,
     code: 'ENOENT',
     syscall: 'open',
     path: '/path/to/project/.next/server/app/api/dummy/[signal_id]/something/[__metadata_id__]/route/app-paths-manifest.json'
   }

5. Attempt removing the .next folder or clearing caches (e.g., rm -rf .next), then rerun npm run dev – the error persists.

6. Build and run in production mode (npm run build && npm run start) – the error does not occur.

Current vs. Expected behavior

Current Behavior:

• The development server throws the above ENOENT error whenever a request is made to /api/dummy/[signal_id]/something.
• Clearing the .next folder does not fix the issue.
• Production mode builds and runs without error.

Expected Behavior:

• The development server should not crash or fail to find app-paths-manifest.json when making requests to the API route.
• The dev environment should run as smoothly as production does.

Provide environment information

npx --no-install next info
/bin/sh: yarn: command not found

Operating System:
  Platform: darwin
  Arch: arm64
  Version: Darwin Kernel Version 23.6.0: Mon Jul 29 21:14:04 PDT 2024; root:xnu-10063.141.2~1/RELEASE_ARM64_T8122
  Available memory (MB): 16384
  Available CPU cores: 8
Binaries:
  Node: 22.12.0
  npm: 10.9.0
  Yarn: N/A
  pnpm: 9.15.0
Relevant Packages:
  next: 15.1.7 // There is a newer version (15.2.0) available, upgrade recommended! 
  eslint-config-next: 15.1.7
  react: 19.0.0
  react-dom: 19.0.0
  typescript: 5.5.4
Next.js Config:
  output: N/A
 ⚠ There is a newer version (15.2.0) available, upgrade recommended! 
   Please try the latest canary version (`npm install next@canary`) to confirm the issue still exists before creating a new issue.
   Read more - https://nextjs.org/docs/messages/opening-an-issue
theo.redlon@Theos-MacBook-Air exlog-sparrowhawk-webapp %

Which area(s) are affected? (Select all that apply)

Not sure

Which stage(s) are affected? (Select all that apply)

next dev (local)

Additional context

No response