`outputFileTracingIncludes` Not Including Files in App Router Route with Dynamic `fs.readFile`

[neelbrahmakshatriya]

Link to the code that reproduces this issue

https://shadcn-studio-internal-staging.vercel.app/blocks

To Reproduce

1. Create a Next.js 15 app using App Router.
2. Add some .tsx files in src/registry/new-york/blocks/.
3. In a route like src/app/(blocks-inner-pages)/blocks/[category]/[section]/page.tsx, call a function from the src/lib/registry.ts file that calls fs.readFile(...) pointing to the files mentioned in the second step.
4. Add outputFileTracingIncludes targeting that route in next.config.ts like the following:

import path from 'path'
import type { NextConfig } from 'next'

const nextConfig: NextConfig = {
  outputFileTracingIncludes: {
    './src/app/(blocks-inner-pages)/blocks/[category]/[section]/page.tsx': [
      './src/registry/new-york/blocks/**/*.tsx',
      './src/lib/registry.ts',
      './src/registry/registry-blocks.ts'
    ]
  }

5. Run next build and observe that files are not present in .next.

Current vs. Expected behavior

Problem

Despite using outputFileTracingIncludes correctly to include files used via dynamic fs.readFile() calls in a server component route, the files are not being traced, copied, or included in the .next build output - either locally or on Vercel.

---

Details

• I'm dynamically reading .tsx files at runtime using:

fs.readFile(path.join(process.cwd(), file.path), 'utf-8')

• The files are stored in:
  src/registry/new-york/blocks/**/*.tsx

• The code that calls fs.readFile lives inside the src/lib/registry.ts file and the function is being called from the following:
  src/app/(blocks-inner-pages)/blocks/[category]/[section]/page.tsx

• My next.config.ts includes:

import type { NextConfig } from 'next'

const nextConfig: NextConfig = {
  outputFileTracingIncludes: {
    './src/app/(blocks-inner-pages)/blocks/[category]/[section]/page.tsx': ['./src/registry/new-york/blocks/**/*.tsx', './src/lib/registry.ts', './src/registry/registry-blocks.ts']
  }
}

---

Actual Behavior

• After running next build, no files from registry/new-york/blocks appear in .next/ output.

• Confirmed with:

  find .next -type f | grep new-york/blocks

• This also causes fs.readFile to fail in the deployed app on Vercel because the files are missing.

---

Expected Behavior

All files in src/registry/new-york/blocks should be included in the .next build output and deployed to Vercel so they are available for runtime access via fs.readFile().

Provide environment information

Operating System:
  Platform: darwin
  Arch: arm64
  Version: Darwin Kernel Version 24.2.0: Fri Dec  6 18:40:14 PST 2024; root:xnu-11215.61.5~2/RELEASE_ARM64_T8103
  Available memory (MB): 8192
  Available CPU cores: 8
Binaries:
  Node: 22.12.0
  npm: 10.9.0
  Yarn: 1.22.19
  pnpm: 10.6.2
Relevant Packages:
  next: 15.3.2 // There is a newer version (15.3.3) available, upgrade recommended! 
  eslint-config-next: 15.3.2
  react: 19.1.0
  react-dom: 19.1.0
  typescript: 5.5.4
Next.js Config:
  output: N/A

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

Runtime

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

next build (local), Vercel (Deployed)

Additional context

No response

[github-actions]

We could not detect a valid reproduction link. Make sure to follow the bug report template carefully.

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Useful Resources

• How to Contribute to Open Source (Next.js)
• How to create a Minimal, Complete, and Verifiable example
• Reporting a Next.js bug
• Next.js Triaging issues