Vercel + pages router + basePath + middleware - Full roundtrip when client navigating to index page

[jpb06]

Link to the code that reproduces this issue

https://github.com/jpb06/next-repro-404-index.json

To Reproduce

The issue only happens while deployed on Vercel.

1: Head to repro sub page. 2: Click on the Home link.

Current vs. Expected behavior

Current behavior

• We are doing a client navigation, but a full roundtrip is occurring when navigating from /yolo to /.
• We get a 404 on theindex.json file (prefetch), even though that file exists.

Expected behavior

• Client navigation should not cause a full roundtrip.

Provide environment information

Operating System:
  Platform: darwin
  Arch: arm64
  Version: Darwin Kernel Version 23.5.0: Wed May  1 20:12:58 PDT 2024; root:xnu-10063.121.3~5/RELEASE_ARM64_T6000
  Available memory (MB): 16384
  Available CPU cores: 10
Binaries:
  Node: 20.10.0
  npm: 10.2.3
  Yarn: 1.22.21
  pnpm: 9.1.3
Relevant Packages:
  next: 14.2.3 // Latest available version is detected (14.2.3).
  eslint-config-next: 14.2.3
  react: 18.3.1
  react-dom: 18.3.1
  typescript: 5.4.5
Next.js Config:
  output: N/A

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

Middleware, Navigation, Pages Router

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

Vercel (Deployed)

Additional context

No response

[jpb06]

Potential duplicate of 65745

[hscstudio]

I found bug about Link with basePath #66660 maybe this is related

[nextjs-bot]

This issue has been automatically marked as stale due to inactivity. It will be closed in 7 days unless there’s further input. If you believe this issue is still relevant, please leave a comment or provide updated details. Thank you.

[nextjs-bot]

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