Next.js standalone bloat: instrumentation uses process.cwd() for buildDir resolution

[an2n]

When using standalone together with turbopack, importing and running
@fortedigital/nextjs-cache-handler/instrumentation can make the standalone output huge
(it starts including many project/repo files).

During next build --turbo, process.cwd() is the project root. With output: "standalone" enabled,
Next.js output tracing can then pull in far more files than needed into the standalone output.

The tracer performs static analysis to determine which files need to be included in the standalone output. When it encounters path.join(process.cwd(), <dynamic_variable>), it cannot determine what path will be accessed at runtime and therefor includes the project root to ensure no files are missing at runtime.

Versions

• Next.js: 15.5.9
• @fortedigital/nextjs-cache-handler: 2.3.2

Reproduction

1. Configure Next.js with output: "standalone".
2. Import and call registerInitialCache from @fortedigital/nextjs-cache-handler/instrumentation.
3. Run next build --turbo.
4. Inspect .next/standalone and see many unrelated repo files included.

I’m happy to open a PR for this change!

[AyronK]

Hey @an2n thanks for reporting, if you have an idea how to address it, please do, contributions are welcome.

[an2n]

So instead of allowing buildDir as a relative path, pass it as an absolute path to opt out of dynamic path resolution. I will open a PR :)

[AyronK]

@an2n ah right, so just allow absolute paths here I guess?

  const nextJsPath = path.join(
    process.cwd(),
    options.buildDir ?? DEFAULT_BUILD_DIR,
  );

[an2n]

@an2n ah right, so just allow absolute paths here I guess?

  const nextJsPath = path.join(
    process.cwd(),
    options.buildDir ?? DEFAULT_BUILD_DIR,
  );

Yes, that’s right. Otherwise nft will trace it as a dynamic path and pull everything.