Turborepo: turbo.json not copied during build, causing build failures

[mario-loomia]

Description

When deploying a Turborepo monorepo with Railpack, the turbo.json configuration file is not being copied into the build context during the install step, which causes the build step to fail with:

x Could not find turbo.json or turbo.jsonc.

Reproduction

1. Create a Turborepo monorepo with a turbo.json file
2. Deploy to Railway using Railpack
3. Railpack auto-generates a build plan
4. The install step copies package.json files but NOT turbo.json
5. The build step runs npx turbo run build --filter=api but fails because turbo.json is missing

Expected Behavior

turbo.json should be automatically included in the build context when Railpack detects a Turborepo project (detects turbo.json in the repo).

Actual Behavior

The auto-generated build plan only copies dependency-related files (package.json, pnpm-lock.yaml, etc.) but skips project-level config files like turbo.json.

Workaround

Currently no workaround found. Attempting to add custom build steps to railpack.json but unclear how to include files in the intermediate layers.

Environment

• Railpack version: 0.16.0
• Node version: 22.22.0
• Package manager: pnpm 10.24.0
• Monorepo structure: 22 packages

[iloveitaly]

@mario-loomia what does your plan output look like?

Here's an example plan output for a turborepo example:

And here's the package.json:

{
  "name": "node-turborepo",
  "private": true,
  "scripts": {
    "build": "turbo build",
    "dev": "turbo dev",
    "start": "cd apps/web && npm start",
    "lint": "turbo lint",
    "format": "prettier --write \"**/*.{ts,tsx,md}\""
  },
  "devDependencies": {
    "prettier": "^3.5.0",
    "turbo": "^2.4.1",
    "typescript": "5.7.3"
  },
  "engines": {
    "node": ">=18"
  },
  "packageManager": "npm@10.9.2",
  "workspaces": [
    "apps/*",
    "packages/*"
  ]
}

Railpack expects the install step to be primarily concerned with installing npm packages, not in actually building the project. In the install step, a limited set of files are available to the scripts in that step. This is to optimize the layer cache so builds are fast.

My guess is what's going on in your situation is you're attempting to build the project during the install step instead of installing packages from npm into the install step and then building the project within the build step. Does that sound right to you?