git:20260831.0978e7e to git:20260905.a73d7ea

---

name: git-post-merge-cleanup

description: >-

Rules, safety constraints, and automated procedures for post-merge local Git cleanup,

synchronizing main with GitHub, deleting stale local branches, and performing deep

repository garbage collection (git gc, reflog expire, prune) strictly upon explicit human user request.

---

# Git Post-Merge Repository & Branch Cleanup Skill

This skill defines the official protocol and step-by-step procedures for cleaning up local development branches, pulling the latest `main` from GitHub after a Pull Request is merged, and executing deep Git repository garbage collection and maintenance.

---

## 1. Strict Permission & Trigger Boundary

> [!IMPORTANT]

> **EXPLICIT HUMAN INSTRUCTION ONLY**:

> AI agents MUST NEVER run local branch deletions, branch resets, or aggressive garbage collection automatically.

> This workflow is triggered **ONLY** when the human user explicitly instructs the agent to perform cleanup (e.g. *"clean up local branches"*, *"sync main and do git gc"*, *"I merged the PR, please clean up"*).

>

> The typical workflow is:

> 2. The human user reviews and merges the Pull Request on GitHub.

> 3. The human user prompts the AI agent to perform local cleanup.

> 4. The AI agent executes the safe post-merge cleanup runbook below.

---

## 2. Core Cleanup Principles

1. **Safety-First Working Tree Verification**: Never switch branches or run destructive cleanups if there are uncommitted changes or uncommitted work in progress.

2. **Main as the Source of Truth**: Always switch to `main` and pull from `origin/main` first so that the newly merged PR code and history are fully present locally before deleting the feature branch.

4. **Remote Reference Pruning**: Prune stale remote tracking branches (`git fetch --prune origin`) to keep the remote tracking tree clean.

5. **Deep Garbage Collection**: Prune unreachable reflog entries (`git reflog expire --expire=now --all`) and optimize the local object store (`git gc --prune=now --aggressive`) to keep the `.git` directory small, fast, and healthy.

6. **Zero Stale Branches**: After cleanup, only `main` remains as the active local branch.

---

## 3. Step-by-Step Cleanup Runbook

When the human user requests post-merge cleanup, execute these exact steps in sequence:

### Step 1: Verify Working Directory State

Ensure there are no unstaged modifications or stash conflicts:

```bash

git status

```

If dirty, stop and check if there are uncommitted files that need to be preserved.

### Step 2: Switch to `main` and Pull Latest Upstream

Switch to the primary release branch and pull the merged changes from GitHub:

```bash

git switch main

git pull origin main

```

### Step 3: Prune Remote Tracking Branches

Synchronize and remove remote branch references that were deleted on GitHub after PR merge:

```bash

git fetch --prune origin

```

### Step 4: Identify & Delete Local Feature Branches

List all local branches to inspect what needs to be removed:

```bash

git branch

```

```bash

# Safe delete merged branches:

git branch -d <branch-name>

# If GitHub used Squash & Merge or Rebase & Merge (which changes commit hashes):

git branch -D <branch-name>

```

Or delete all local branches except `main` in one command:

```bash

git branch | grep -v "^\* main$" | grep -v "^ main$" | xargs -r git branch -D

```

### Step 5: Expire Reflogs & Run Aggressive Garbage Collection

Clean up dangling commits, unreachable objects, and optimize packfiles:

```bash

git reflog expire --expire=now --all

git gc --prune=now --aggressive

```

### Step 6: Verify Final Repository State

Verify that only `main` remains and the working tree is clean:

```bash

git branch

git status

```

---