Claude Code Turborepo Cache Miss — Fix (2026)

Q: If That Doesn’t Work

Alternative 1: Add .claude/ to .gitignore so Turborepo’s git-based hashing excludes it automatically Alternative 2: Use inputs: ["src/**"] explicitly in every task to only hash source files Check: Run npx turbo build --summarize and inspect .turbo/runs/ for the full hash breakdown

Last updated: April 20, 2026

The Error

 Tasks:    12 successful, 12 total
 Cached:    0 cached, 12 total
   Time:    4m 32s
# Expected most tasks to be cached but got 0 cache hits
# Or in verbose mode:
[turbo] cache miss, executing task {build}
  Hash: abc123def456
  Inputs changed:
    - .claude/settings.json (added)
    - CLAUDE.md (modified)

The Fix

Exclude Claude Code files from turbo hash inputs

// turbo.json
{
  "$schema": "https://turbo.build/schema.json",
  "globalDependencies": ["tsconfig.json"],
  "globalPassThroughEnv": ["ANTHROPIC_API_KEY"],
  "tasks": {
    "build": {
      "inputs": [
        "src/**",
        "package.json",
        "tsconfig.json",
        "!.claude/**",
        "!CLAUDE.md",
        "!**/*.test.ts"
      ],
      "outputs": ["dist/**"]
    }
  }
}

Verify what is busting the cache

# Run with hash debugging to see exact inputs
npx turbo build --dry=json | python3 -c "
import sys, json
data = json.load(sys.stdin)
for task in data.get('tasks', []):
    print(f\"{task['taskId']}: {task['cache']['status']}\")
    if task['cache']['status'] != 'HIT':
        print(f\"  Hash inputs: {task.get('inputs', {}).get('files', [])[:5]}...\")
"

Verify the fix:

# Run build twice — second should be cached
npx turbo build && npx turbo build 2>&1 | grep "Cached"
# Expected: Cached: 12 cached, 12 total (on second run)

Why This Happens

Turborepo generates a content hash of all input files to determine cache validity. By default, it hashes every file in the package directory. When Claude Code creates or modifies files like CLAUDE.md, .claude/settings.json, or generates temporary files, these changes alter the hash even though they don’t affect build output. Each Claude Code session that touches these files invalidates the entire cache, causing full rebuilds that waste CI minutes.

If That Doesn’t Work

Alternative 1: Add .claude/ to .gitignore so Turborepo’s git-based hashing excludes it automatically
Alternative 2: Use inputs: ["src/**"] explicitly in every task to only hash source files
Check: Run npx turbo build --summarize and inspect .turbo/runs/ for the full hash breakdown

Prevention

Add to your CLAUDE.md:

Exclude .claude/ and CLAUDE.md from turbo.json task inputs. Always specify explicit inputs arrays in turbo.json rather than relying on defaults. After modifying turbo.json, run builds twice to verify caching works.

This fix also applies if you see variations of this error:

Connection or process errors with similar root causes in the same subsystem
Timeout variants where the operation starts but does not complete
Permission variants where access is denied to the same resource
Configuration variants where the same setting is missing or malformed

If your specific error message differs slightly from the one shown above, the fix is likely the same. The key indicator is the operation that failed (shown in the stack trace) rather than the exact wording of the message.

Frequently Asked Questions

Does this error affect all operating systems?

This error can occur on macOS, Linux, and Windows (WSL). The exact error message may differ slightly between platforms, but the root cause and fix are the same. macOS users may see additional Gatekeeper or notarization prompts. Linux users should check that the relevant system packages are installed. Windows users should ensure they are running inside WSL2, not native Windows.

Will this error come back after updating Claude Code?

Updates can occasionally reintroduce this error if the update changes default configurations or dependency requirements. After updating Claude Code, verify your project still builds and runs correctly. If the error returns, reapply the fix and check the changelog for breaking changes.

Can this error cause data loss?

No, this error occurs before or during an operation and does not corrupt existing files. Claude Code’s edit operations are atomic — they either complete fully or not at all. However, if the error occurs during a multi-step operation, you may have partial changes that need to be reviewed with git diff before continuing.

How do I report this error to Anthropic if the fix does not work?

Open an issue at github.com/anthropics/claude-code with: (1) the full error message including stack trace, (2) your Node.js version (node --version), (3) your Claude Code version (claude --version), (4) your operating system and version, and (5) the command or operation that triggered the error.

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