🏥 CI Failure Investigation - Run #21238699729

Summary

The CI workflow failed with a massive parallel failure pattern affecting 13 out of 30+ jobs. This is highly unusual - multiple unrelated jobs (lint, build, security scans, platform-specific builds) all failed simultaneously while integration and test jobs passed successfully.

Key Anomaly: The same commit (0a4236d) produced both a successful run (#21238699728) and this failed run (#21238699729) at nearly the same time.

Failure Details

• Run: 21238699729
• Commit: 0a4236d3643433db952e01a026381cb0b172b6fa
• Message: "Add debug logging to 4 Go files for better troubleshooting ([log] Add debug logging to 4 Go files for better troubleshooting #11203)"
• Trigger: Push to main branch
• Timestamp: 2026-01-22 06:37:12 UTC
• Pattern: Massive parallel failure (13 jobs)

Investigation Limitations

⚠️ INCOMPLETE INVESTIGATION - Unable to access workflow logs directly:

• API returned 403 Forbidden for job logs (requires admin rights)
• Investigation based on job status, historical patterns, and commit analysis
• Manual log review required for definitive root cause

Failed Jobs (13 total)

Build & Lint Jobs (4)

• ❌ build - Main build job
• ❌ lint-go - Go linting
• ❌ update - Dependency updates
• ❌ actions-build - Actions build

Security Scans (4)

• ❌ security - General security scan
• ❌ Security Scan: actionlint - Action linting
• ❌ Security Scan: poutine - Poutine security analysis
• ❌ Security Scan: zizmor - Zizmor security scan

Platform-Specific Builds (2)

• ❌ Build & Test on windows-latest - Windows build
• ❌ Build & Test on macos-latest - macOS build

Other Jobs (3)

• ❌ Alpine Container Test - Container testing
• ❌ mcp-server-compile-test - MCP server compilation
• ❌ audit - Security audit

✅ Jobs That Passed (17)

All of these succeeded:

• validate-yaml, bench, test, lint-js, fuzz
• All 12 integration test matrix jobs
• Both JS test jobs

Root Cause Analysis (3 Scenarios)

Scenario 1: GitHub Actions Infrastructure Issue (70% confidence)

Evidence:

1. Simultaneous parallel failures - Highly unusual pattern
2. Same commit, different outcomes - Run #21238699728 ✅ succeeded, #21238699729 ❌ failed
3. Unrelated jobs affected - No common dependency between lint, build, security scans
4. 403 API errors - Suggests infrastructure/permissions anomaly
5. Recent failure spike - 5 consecutive failures: 21238712945, 21238699729, 21237714673, 21237334152, 21236961755

Root cause hypothesis:

• GitHub Actions runner pool instability
• Resource exhaustion (memory/CPU/disk) on runner host
• Network connectivity issues affecting multiple runners
• Concurrency limit reached (workflow has cancel-in-progress: true for many jobs)

Scenario 2: Go Formatting/Build Issue (20% confidence)

Pattern from issue #10130: GO_FORMAT_CHECK_FAILED is the #1 recurring CI failure

Evidence:

• Failed jobs include lint-go and build
• Historical pattern shows formatting blocks CI frequently
• Commit modified Go files (added debug logging)

Counter-evidence:

• ✅ test job passed (depends on same Go code)
• Integration tests all passed
• Same commit succeeded in run #21238699728

Scenario 3: Dependency/Cache Corruption (10% confidence)

Hypothesis:

• Go module cache corruption
• npm cache inconsistency
• Binary cache mismatch

Counter-evidence:

• Too many unrelated jobs affected
• Security scan jobs don't share build dependencies

Historical Context

Recent Failure Pattern

Run 21238712945: FAILED - Same commit
Run 21238699729: FAILED - This investigation
Run 21238699728: SUCCESS - Same commit
Run 21237714673: FAILED
Run 21237334152: FAILED
Run 21236961755: FAILED

Pattern: Multiple failures in quick succession, but also successes mixed in (same commit).

Similar Past Issues

From investigation database:

• [CI Failure Doctor] CI Failure Investigation - Massive workflow commit without validation (Run #21044916258) #10130: Massive workflow commit without validation (GO_FORMAT_CHECK_FAILED pattern)
• [CI Failure Doctor] CI Failure Investigation - SBOM Upload Timing Change (Run #21102091204) #10504: SBOM Upload Timing Change (infrastructure timing issue)
• [CI Failure Doctor] CI Failure Doctor: close_older_issues.test.cjs uses Jest instead of Vitest #10895: Jest vs Vitest test framework mismatch

None match this exact failure pattern (13 simultaneous parallel failures).

Recommended Actions

Immediate (Investigation)

1. Manual log review - Visit workflow run #21238699729 to access actual error logs

2. Compare with successful run - Check run #21238699728 (same commit, succeeded)

3. Check GitHub Actions status - Verify no reported incidents at https://www.githubstatus.com/

4. Retry the workflow - Re-run failed jobs to see if issue is transient

If Infrastructure Issue (Scenario 1)

• ✅ No action needed - transient GitHub Actions infrastructure glitch
• 📝 Document the pattern for future reference
• 🔄 Set up monitoring for similar failure patterns

If Go Formatting Issue (Scenario 2)

make agent-finish  # Run full validation

Or step-by-step:

make fmt           # Format Go, JS, JSON
make build         # Rebuild binary
make recompile     # Regenerate lock files  
make test-unit     # Run tests

If Dependency Issue (Scenario 3)

# Clear caches
go clean -modcache
rm -rf node_modules actions/setup/js/node_modules
go mod download
cd actions/setup/js && npm ci

Prevention Strategies

1. Enhanced Monitoring

• Add job-level telemetry to detect parallel failure patterns
• Alert on >5 simultaneous job failures (current threshold: undefined)
• Track runner performance metrics

2. Improved Diagnostics

# Add to CI jobs
- name: Diagnose runner environment
  if: failure()
  run: |
    echo "Runner: $RUNNER_NAME"
    echo "Runner OS: $RUNNER_OS"
    df -h
    free -m
    uptime

3. Concurrency Management

# Review concurrency settings
concurrency:
  group: ci-${{ github.ref }}-${{ matrix.job }}
  cancel-in-progress: true  # May cause race conditions?

4. Retry Logic

# Add automatic retry for transient failures
- uses: nick-invision/retry@v2
  with:
    timeout_minutes: 10
    max_attempts: 3
    command: make build

AI Team Self-Improvement

Suggested addition to .github/copilot/instructions/ci-performance.md:

### 🚨 MASSIVE PARALLEL FAILURE DETECTION

When investigating CI failures, recognize infrastructure vs. code issues:

**Infrastructure failure indicators:**
- ✅ **10+ jobs fail simultaneously** (especially unrelated jobs)
- ✅ **Same commit has both success and failure runs**
- ✅ **403/500 API errors when accessing logs**
- ✅ **No code changes in failed commit** or only minor changes
- ✅ **Integration tests pass, but build/lint fail** (inconsistent pattern)

**Code failure indicators:**
- ✅ **Consistent failure across all runs of same commit**
- ✅ **Related jobs fail** (e.g., all Go jobs, or all JS jobs)
- ✅ **Clear error messages in logs**
- ✅ **Reproducible locally** with `make agent-finish`

**Action:**
- Infrastructure issue: Report to GitHub Support, document, retry
- Code issue: Fix with `make fmt`, `make build`, `make recompile`

**Never assume code issue when pattern suggests infrastructure failure.**

Next Steps

• Manual log review - Access actual error messages from failed jobs
• Compare successful run - Analyze differences with #21238699728
• Retry workflow - Determine if transient or persistent
• Update investigation - Document confirmed root cause
• Implement monitoring - Detect similar patterns in future

Investigation Metadata

{
  "run_id": "21238699729",
  "confidence": "medium",
  "api_access": false,
  "analysis_method": "pattern_based_without_logs",
  "primary_hypothesis": "github_actions_infrastructure_issue",
  "confidence_infrastructure": 0.70,
  "confidence_go_formatting": 0.20,
  "confidence_dependency": 0.10,
  "parallel_failures": 13,
  "total_jobs": 30,
  "failure_rate": 0.43,
  "anomaly_level": "high"
}

⚠️ This investigation is based on job status and historical patterns without direct log access. Manual verification required for definitive root cause.

AI generated by CI Failure Doctor

To add this workflow in your repository, run gh aw add githubnext/agentics/workflows/ci-doctor.md@ea350161ad5dcc9624cf510f134c6a9e39a6f94d. See usage guide.