Git Bisect Debugging

Overview

Use this skill to isolate first-bad commits quickly and reproducibly, so fixes target root cause instead of symptoms.

Scope Boundaries

• Use this skill when the task matches the trigger condition described in description.
• Do not use this skill when the primary task falls outside this skill's domain.

Shared References

• Determinism guidance:
  • references/bisect-determinism-guidance.md

Templates And Assets

• Session log template:
  • assets/bisect-session-log-template.md
• Verification checklist:
  • assets/bisect-checklist.md

Inputs To Gather

• Known good commit and known bad commit.
• Deterministic pass/fail command for classification.
• Environment requirements for reproducible execution.
• Evidence expectations for culprit validation.

Deliverables

• Culprit commit candidate with evidence trail.
• Bisect session log with classified steps.
• Confidence statement and next action recommendation.

Workflow

1. Validate good/bad endpoints and deterministic classifier command.
2. Run bisect and classify commits consistently.
3. Capture classifications in assets/bisect-session-log-template.md.
4. Re-validate candidate culprit around boundary commits.
5. Close with assets/bisect-checklist.md and next-step recommendation.

Quality Standard

• Good/bad endpoints are verified before bisect begins.
• Classification is deterministic and repeatable.
• Culprit claim is supported by reproducible evidence.
• Session records are sufficient for peer audit.

Failure Conditions

• Stop when classification is flaky or environment-dependent.
• Stop when no reliable good/bad endpoints can be identified.
• Escalate when interacting commits prevent single-commit isolation.