git-worktrees

Git Worktrees

Overview

Git worktrees create isolated workspaces sharing the same repository, allowing work on multiple branches simultaneously without switching.

Core principle: Systematic directory selection + safety verification = reliable isolation.

When to Use

• Starting new feature that needs isolation
• Working on multiple features in parallel
• Experimenting without affecting main workspace
• Running tests on different branches simultaneously
• PM assigns parallel tasks to multiple specialists

Directory Selection Priority

1. Check Existing Directories

# Check in priority order
ls -d .worktrees 2>/dev/null     # Preferred (hidden)
ls -d worktrees 2>/dev/null      # Alternative

If found: Use that directory. If both exist, .worktrees wins.

2. Check CLAUDE.md

grep -i "worktree.*director" CLAUDE.md 2>/dev/null

If preference specified: Use it without asking.

3. Default to .worktrees/

If no directory exists and no preference, create .worktrees/.

Safety Verification

For Project-Local Directories

MUST verify directory is ignored before creating worktree:

# Check if directory is ignored
git check-ignore -q .worktrees 2>/dev/null

If NOT ignored:

1. Add to .gitignore
2. Commit the change
3. Proceed with worktree creation

Why critical: Prevents accidentally committing worktree contents.

Creation Steps

Step 1: Prepare

# Get project name
project=$(basename "$(git rev-parse --show-toplevel)")

# Ensure .worktrees is ignored
if ! git check-ignore -q .worktrees 2>/dev/null; then
  echo ".worktrees/" >> .gitignore
  git add .gitignore
  git commit -m "chore: ignore .worktrees directory"
fi

Step 2: Create Worktree

# Create worktree with new branch
BRANCH_NAME="feature/your-feature"
git worktree add .worktrees/$BRANCH_NAME -b $BRANCH_NAME

# Navigate to worktree
cd .worktrees/$BRANCH_NAME

Step 3: Run Project Setup

Auto-detect and run appropriate setup:

# Node.js
[ -f package.json ] && npm install

# Python
[ -f requirements.txt ] && pip install -r requirements.txt
[ -f pyproject.toml ] && poetry install

# Go
[ -f go.mod ] && go mod download

# Rust
[ -f Cargo.toml ] && cargo build

Step 4: Verify Clean Baseline

# Run tests to ensure worktree starts clean
npm test        # Node.js
pytest          # Python
go test ./...   # Go
cargo test      # Rust

If tests fail: Report failures, ask whether to proceed. If tests pass: Ready to work.

Step 5: Report Location

Worktree ready at /path/to/project/.worktrees/feature-name
Tests passing (N tests, 0 failures)
Ready to implement [feature-name]

Managing Worktrees

List All Worktrees

git worktree list

Remove Worktree

# After merging feature branch
git worktree remove .worktrees/feature-name

# Force remove (if dirty)
git worktree remove --force .worktrees/feature-name

# Clean up stale worktrees
git worktree prune

Switch Between Worktrees

# Each worktree is a separate directory
cd .worktrees/feature-auth     # Work on auth
cd .worktrees/feature-payment  # Work on payment
cd /path/to/main/repo          # Back to main

Integration with Super Agent

For PM

When assigning parallel tasks:

## Task Assignment

**Task 1.1** - Backend API (James)
Worktree: `.worktrees/sprint-1-backend`
Branch: `feature/sprint-1-backend`

**Task 1.2** - Frontend UI (Sarah)
Worktree: `.worktrees/sprint-1-frontend`
Branch: `feature/sprint-1-frontend`

For Specialists

Before starting isolated work:

# 1. Create worktree
git worktree add .worktrees/my-feature -b feature/my-feature

# 2. Setup dependencies
cd .worktrees/my-feature && npm install

# 3. Verify baseline
npm test

# 4. Start work
# ... implement feature ...

# 5. When done, merge and cleanup
git checkout main
git merge feature/my-feature
git worktree remove .worktrees/my-feature
git branch -d feature/my-feature

Quick Reference

Situation	Action
.worktrees/ exists	Use it (verify ignored)
worktrees/ exists	Use it (verify ignored)
Both exist	Use .worktrees/
Neither exists	Create .worktrees/
Directory not ignored	Add to .gitignore + commit
Tests fail	Report failures + ask
Feature complete	Merge + remove worktree

Common Mistakes

Skipping ignore verification

Problem: Worktree contents get tracked Fix: Always git check-ignore before creating

Not cleaning up worktrees

Problem: Stale worktrees accumulate Fix: git worktree remove after merge

Forgetting to setup dependencies

Problem: Build fails in worktree Fix: Always run npm install / pip install after creation

Red Flags

Never:

• Create worktree without verifying it's ignored
• Skip baseline test verification
• Leave stale worktrees after merge
• Commit from wrong worktree

Always:

• Follow directory priority
• Verify directory is ignored
• Run project setup
• Verify clean baseline
• Clean up after merge