Github Pipeline Diagnostics

GitHub Pipeline Diagnostics Skill

Use repository, workflow run, job, and log evidence from GitHub Actions to identify CI/CD failure causes, map them to common remediation patterns, and return a concise diagnosis with validation evidence.

When to invoke

• "Diagnose why this GitHub Actions workflow failed."
• "Triage a failed CI build or deployment job."
• "Analyze failed job logs and recommend remediation steps."
• "Investigate Actions permissions, OIDC, cache, dependency, build, Docker, or deployment failures."

Criteria

GitHub Actions API reference

Workflow Runs

# List recent runs (all statuses)
gh run list --repo {owner}/{repo} --limit 10

# Filter by status
gh run list --repo {owner}/{repo} --status failure --limit 5

# View specific run details
gh run view {run_id} --repo {owner}/{repo}

# View failed job logs
gh run view {run_id} --repo {owner}/{repo} --log-failed

# Re-run failed jobs
gh run rerun {run_id} --repo {owner}/{repo} --failed

REST API endpoints

Run status values

Run conclusion values

Common failure patterns

1. Dependency Install Failures

Symptoms: npm ci, yarn install, or pip install step fails Causes: Lock file out of sync, registry down, version conflicts Remediation:

1. Check if package-lock.json / yarn.lock is committed
2. Compare lock file with package.json versions
3. Check npm/PyPI registry status
4. Clear caches and re-run

2. Build/Compile Errors

Symptoms: tsc, go build, dotnet build step fails Causes: Type errors, missing imports, breaking API changes Remediation:

1. Read the error message from the failed step output
2. Identify the file and line number
3. Suggest specific code fix
4. Recommend running build locally first

3. Test Failures

Symptoms: jest, pytest, go test step fails Causes: Flaky tests, environment differences, assertion failures Remediation:

1. Identify which tests failed
2. Use the test-coverage skill for detailed test analysis
3. Check if tests pass locally

4. Docker Build Failures

Symptoms: docker build or docker push step fails Causes: Missing base image, COPY source not found, registry auth Remediation:

1. Check Dockerfile COPY paths match repo structure
2. Verify base image exists and tag is valid
3. Check registry credentials in secrets

5. Deployment Failures

Symptoms: kubectl apply, helm upgrade, or az webapp deploy fails Causes: Cluster unreachable, image pull error, resource limits Remediation:

1. Check cluster connectivity (credentials, RBAC)
2. Verify image exists in registry
3. Check resource quotas and limits

Output template

Return exactly this structure:

  ## Pipeline Diagnosis

**Status:** PASS | FAIL | BLOCKED
**Summary:** {one_sentence_summary}

  ### Details
**Repository:** {owner}/{repo}
**Workflow:** {workflow_name}
**Run:** #{run_number} ({run_id})
**Branch:** {branch} | **Event:** {event} | **Status:** {conclusion}

  #### Failed Jobs
| Job | Step | Status | Duration |
|-----|------|--------|----------|
| {job_name} | {step_name} | {conclusion} | {duration} |

  #### Root Cause
{analysis}

  #### Remediation Steps
1. {step_1}
2. {step_2}
3. {step_3}

  #### Recommended Handoff
- {handoff_recommendation}

  ### Validation
- Workflow run data fetched: {pass_fail_result_and_evidence}
- Failed job and step identified: {pass_fail_result_and_evidence}
- Remediation mapped to observed evidence: {pass_fail_result_and_evidence}

Limits

• Do not use this skill for test coverage strategy; use test-coverage (skill) instead when coverage, quality gates, or test signals are the primary concern.
• Do not use this skill for GitHub CLI mechanics; use github-cli (skill) instead when the user needs general repository or workflow command help.
• Do not use this skill for Kubernetes operations; use kubectl-cli instead when the work is direct cluster operation.
• Do not use this skill for Helm chart fixes; use helm-cli instead when the work is chart packaging or release management.
• Do not use this skill to re-run or mutate workflow state unless the user explicitly requested that action.

Related primitives

Quality gate

• Fetched real workflow run data before diagnosing.
• Identified specific failed job and step.
• Provided root cause analysis tied to run, job, or log evidence.
• Included actionable remediation steps.
• Suggested follow-up when appropriate (test-coverage for tests, @open-horizons-terraform for infra).
• Used the output template format with status, summary, details, and validation evidence.