Break the Loop - Deep Bug Analysis

When debug is complete, use this command for deep analysis to break the "fix bug -> forget -> repeat" cycle.

Analysis Framework

Analyze the bug you just fixed from these 5 dimensions:

1. Root Cause Category

Which category does this bug belong to?

Category Characteristics Example

A. Missing Spec No documentation on how to do it New feature without checklist

B. Cross-Layer Contract Interface between layers unclear API returns different format than expected

C. Change Propagation Failure Changed one place, missed others Changed function signature, missed call sites

D. Test Coverage Gap Unit test passes, integration fails Works alone, breaks when combined

E. Implicit Assumption Code relies on undocumented assumption Timestamp seconds vs milliseconds

2. Why Fixes Failed (if applicable)

If you tried multiple fixes before succeeding, analyze each failure:

• Surface Fix: Fixed symptom, not root cause

• Incomplete Scope: Found root cause, didn't cover all cases

• Tool Limitation: grep missed it, type check wasn't strict

• Mental Model: Kept looking in same layer, didn't think cross-layer

3. Prevention Mechanisms

What mechanisms would prevent this from happening again?

Type Description Example

Documentation Write it down so people know Update thinking guide

Architecture Make the error impossible structurally Type-safe wrappers

Compile-time TypeScript strict, no any Signature change causes compile error

Runtime Monitoring, alerts, scans Detect orphan entities

Test Coverage E2E tests, integration tests Verify full flow

Code Review Checklist, PR template "Did you check X?"

4. Systematic Expansion

What broader problems does this bug reveal?

• Similar Issues: Where else might this problem exist?

• Design Flaw: Is there a fundamental architecture issue?

• Process Flaw: Is there a development process improvement?

• Knowledge Gap: Is the team missing some understanding?

5. Knowledge Capture

Solidify insights into the system:

• Update .trellis/spec/guides/ thinking guides

• Update .trellis/spec/cli/backend/ or cli/frontend/ docs

• Create issue record (if applicable)

• Create feature ticket for root fix

• Update check commands if needed

Output Format

Please output analysis in this format:

Bug Analysis: [Short Description]

1. Root Cause Category

• Category: [A/B/C/D/E] - [Category Name]
• Specific Cause: [Detailed description]

2. Why Fixes Failed (if applicable)

1. [First attempt]: [Why it failed]
2. [Second attempt]: [Why it failed] ...

3. Prevention Mechanisms

4. Systematic Expansion

• Similar Issues: [List places with similar problems]
• Design Improvement: [Architecture-level suggestions]
• Process Improvement: [Development process suggestions]

5. Knowledge Capture

• [Documents to update / tickets to create]

Core Philosophy

The value of debugging is not in fixing the bug, but in making this class of bugs never happen again.

Three levels of insight:

• Tactical: How to fix THIS bug

• Strategic: How to prevent THIS CLASS of bugs

• Philosophical: How to expand thinking patterns

30 minutes of analysis saves 30 hours of future debugging.

After Analysis: Immediate Actions

IMPORTANT: After completing the analysis above, you MUST immediately:

Update spec/guides - Don't just list TODOs, actually update the relevant files:

• If it's a cross-platform issue → update cross-platform-thinking-guide.md

• If it's a cross-layer issue → update cross-layer-thinking-guide.md

• If it's a code reuse issue → update code-reuse-thinking-guide.md

• If it's domain-specific → update cli/backend/.md or cli/frontend/.md

Sync templates - After updating .trellis/spec/ , sync to src/templates/markdown/spec/

Commit the spec updates - This is the primary output, not just the analysis text

The analysis is worthless if it stays in chat. The value is in the updated specs.