ccc-debug-session

Debug Session — Structured Investigation

Starting debug session for: {{input}}

Phase 1: Gather Context

1. Recent changes: Run git log --oneline -10 and git diff HEAD~3 to see what changed recently
2. Error reproduction: Identify the exact error message, stack trace, or unexpected behavior
3. Related files: Search for files related to the issue description
4. Previous fixes: Check tasks/lessons.md for related past fixes
5. Git blame: Identify when the relevant code was last changed

Phase 2: Hypothesis Generation

Generate 3-5 candidate root causes, ranked by likelihood:

HYPOTHESIS 1 (most likely): [description]
  Evidence for: [what supports this]
  Evidence against: [what contradicts this]
  Test: [how to verify]

HYPOTHESIS 2: [description]
  Evidence for: ...
  Evidence against: ...
  Test: ...

Phase 3: Systematic Investigation

For each hypothesis (starting with most likely):

1. Design a minimal test to confirm or eliminate
2. Run the test
3. Document the result
4. If confirmed → proceed to fix. If eliminated → next hypothesis.

IMPORTANT: Do not change code to "try things." Test hypotheses with reads, greps, and targeted experiments first.

Phase 4: Resolution

When root cause is identified:

1. Write a reproduction test FIRST (RED)
2. Implement the minimal fix (GREEN)
3. Verify the fix resolves the original issue
4. Run full test suite to check for regressions
5. Document in tasks/lessons.md:

## [Date] — {{input}}
**Root cause:** [what actually caused it]
**Fix:** [what was changed]
**Lesson:** [what to watch for in the future]
**Prevention:** [rule or test that prevents recurrence]

Output Format

DEBUG SESSION: {{input}}
Status: [INVESTIGATING / ROOT CAUSE FOUND / FIXED / UNRESOLVED]

Hypotheses tested: X/Y
Root cause: [description or "still investigating"]
Fix applied: [yes/no — description]
Tests added: [yes/no — count]
Lessons captured: [yes/no]