D Plan Fix

Core responsibilities:

• Read root cause analysis
• Propose fix approach
• Decompose into atomic tasks
• Define verification criteria

Flow: Load Root Cause → Plan → Verify → Write

• --force — Regenerate plan even if FIX_PLAN.md exists

Required files:

• ./.gtd/debug/current/ROOT_CAUSE.md — Must exist

Output:

• ./.gtd/debug/current/FIX_PLAN.md

Fix the Cause, Not the Symptom

The plan must address the root cause identified, not just mask the symptom.

Aggressive Atomicity

Each plan: 2-3 tasks max. No exceptions.

Side Effect Awareness

Core Principles

Mantra: "Optimize for Evolution, not just Implementation."

• Gall's Law: Reject complexity. Start with the smallest working modular monolith.
• Single Source of Truth: Data must be normalized. If state exists in two places, you have designed a bug.
• Complete Path Principle: Information never teleports. Every producer needs a consumer. Every event needs a handler.
• Testability First: Design "Seams" for every external dependency (Time, Network, Randomness).
• Centralized Resilience: Retry logic/circuit breakers must be at the edge, not scattered.

Blueprint Checklist

• Data Model: Defined schemas (SQL/JSON) with exact types.
• Constraints: What must ALWAYS be true? (e.g., "Balance >= 0").
• Failure Modes: Handling partial failures and data corruption.
• Error Taxonomy: Define Retryable vs Fatal errors.

1. Validate Environment

Bash:

if ! test -f "./.gtd/debug/current/ROOT_CAUSE.md"; then
    echo "Error: No root cause found. Run /d-verify first."
    exit 1
fi

2. Check Existing Plan

Bash:

test -f "./.gtd/debug/current/FIX_PLAN.md"

If exists AND --force NOT set:

• Display: "Using existing plan. Use --force to regenerate."
• Skip to Offer Next

3. Load Root Cause

Read ./.gtd/debug/current/ROOT_CAUSE.md.

Extract:

• Root cause description
• Affected files
• Expected vs actual behavior

4. Plan Fix

Display:

━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
 GTD:DEBUG ► PLANNING FIX
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

4a. Gather Context

Load ROOT_CAUSE.md and affected source files. Use root cause findings to inform design constraints defined in <design_principles>.

4b. Decompose into Tasks

1. Identify all changes needed.
2. Break into atomic tasks (2-3 max) using <task_types>.
3. Define done criteria for each.

4c. Write FIX_PLAN.md

Write to ./.gtd/debug/current/FIX_PLAN.md using this template:

---
created: { date }
root_cause: { brief one-liner }
---

# Fix Plan

## Objective

{What this fix delivers and why}

## Context

- ./.gtd/debug/current/ROOT_CAUSE.md
- {affected source files}

## Architecture Constraints

- **Single Source:** {Where is the authoritative data?}
- **Invariants:** {What must ALWAYS be true?}
- **Resilience:** {How do we handle failures?}
- **Testability:** {What needs to be injected/mocked?}

## Tasks

<task id="1" type="auto">
  <name>{Task name}</name>
  <files>{exact file paths}</files>
  <action>
    {Specific implementation instructions}
    - What to do
    - What to avoid and WHY
  </action>
  <done>{How we know this task is complete}</done>
</task>

<task id="2" type="auto">
  ...
</task>

## Success Criteria

- [ ] Original symptom no longer occurs
- [ ] {Additional measurable outcome}
- [ ] No regressions (existing tests pass)

## Rollback Plan

{How to undo changes if something goes wrong}

5. Verify Plan

Check:

• Tasks are specific (no "fix the bug")
• Done criteria are measurable
• 2-3 tasks max
• All files specified
• Side effects addressed
• Adherence to <prohibitions>

If issues found: Fix before writing.

━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
 GTD:DEBUG ► FIX PLANNED ✓
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

Fix plan written to ./.gtd/debug/current/FIX_PLAN.md

{X} tasks defined

| Task | Name |
|------|------|
| 1 | {name} |
| 2 | {name} |

─────────────────────────────────────────────────────
▶ Next Up
/d-execute — execute the fix plan
─────────────────────────────────────────────────────