Git Integration fails after successful build for rootDirectory=web Next.js app

We have a Vercel Git Integration deployment failing for a Next.js project whose configured Root Directory is `web`.

Project:

  • name: `brenda-voice`
  • rootDirectory: `web`
  • framework: `nextjs`
  • nodeVersion: `24.x`

Failing deployment:

What happens:

  • Build completes successfully.
  • `next build`, TypeScript, and static page generation all finish successfully.
  • After build completion, Vercel marks the deployment as `Error` during finalization.

Exact error from the deployment record:

  • `ENOENT: no such file or directory, lstat ‘/vercel/path0/.next/routes-manifest-deterministic.json’`

Why this looks wrong:

  • The app lives in the `web/` subdirectory.
  • The project is configured with `rootDirectory = web`.
  • The build output is under `/vercel/path0/web/.next`, but finalization appears to be looking under `/vercel/path0/.next` at repo root.

Additional context:

  • Workspace path-length guard passes with zero filename/path violations.
  • Local app build also passes.
  • Recent production deployments for this project are failing with the same post-build behavior.

Is this a known Vercel / Next.js subdirectory-project bug around `routes-manifest-deterministic.json` lookup during deployment finalization? If so, what is the recommended workaround?