Using 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.

Announce at start: "I'm using the using-git-worktrees skill to set up an isolated workspace."

Directory Selection Process

Follow this priority order:

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. Ask User

If no directory exists and no CLAUDE.md preference:

No worktree directory found. Where should I create worktrees?

1. .worktrees/ (project-local, hidden)
2. ~/.config/superpowers/worktrees/<project-name>/ (global location)

Which would you prefer?

Safety Verification

For Project-Local Directories (.worktrees or worktrees)

MUST verify .gitignore before creating worktree:

# Check if directory pattern in .gitignore
grep -q "^\.worktrees/$" .gitignore || grep -q "^worktrees/$" .gitignore

If NOT in .gitignore:

Per Jesse's rule "Fix broken things immediately":

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

Why critical: Prevents accidentally committing worktree contents to repository.

For Global Directory (~/.config/superpowers/worktrees)

No .gitignore verification needed - outside project entirely.

Creation Steps

1. Detect Current Branch and Project Name

ALWAYS use {current-branch}-worktree pattern. DO NOT ask user for branch name.

# Get current branch name
current_branch=$(git branch --show-current)

# Create worktree branch name automatically
worktree_branch="${current_branch}-worktree"

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

Why automatic naming:

• Consistent, predictable pattern
• No user friction
• Clear relationship to parent branch

2. Create Worktree

# Determine full path using worktree_branch
case $LOCATION in
  .worktrees|worktrees)
    path="$LOCATION/$worktree_branch"
    ;;
  ~/.config/superpowers/worktrees/*)
    path="~/.config/superpowers/worktrees/$project/$worktree_branch"
    ;;
esac

# Create worktree with new branch based on current branch
git worktree add "$path" -b "$worktree_branch"
cd "$path"

3. Run Project Setup

Auto-detect and run appropriate setup:

# Node.js
if [ -f package.json ]; then npm install; fi

# Rust
if [ -f Cargo.toml ]; then cargo build; fi

# Python
if [ -f requirements.txt ]; then pip install -r requirements.txt; fi
if [ -f pyproject.toml ]; then poetry install; fi

# Go
if [ -f go.mod ]; then go mod download; fi

4. Report Location

Worktree created at <full-path>
Dependencies installed
Ready for use

Note: This skill does NOT run tests. The caller decides whether to validate the worktree environment.

Quick Reference

Common Mistakes

Skipping .gitignore verification

• Problem: Worktree contents get tracked, pollute git status
• Fix: Always grep .gitignore before creating project-local worktree

Assuming directory location

• Problem: Creates inconsistency, violates project conventions
• Fix: Follow priority: existing > CLAUDE.md > ask

Hardcoding setup commands

• Problem: Breaks on projects using different tools
• Fix: Auto-detect from project files (package.json, etc.)

Example Workflow

You: I'm using the using-git-worktrees skill to set up an isolated workspace.

[Detect current branch: main]
[Check .worktrees/ - exists]
[Verify .gitignore - contains .worktrees/]
[Create worktree: git worktree add .worktrees/main-worktree -b main-worktree]
[Run npm install]

Worktree created at /Users/jesse/myproject/.worktrees/main-worktree
Dependencies installed
Ready for use

Red Flags

Never:

• Create worktree without .gitignore verification (project-local)
• Assume directory location when ambiguous
• Skip CLAUDE.md check
• Ask user for branch name (automatic naming only)
• Deviate from {current-branch}-worktree pattern

Always:

• Follow directory priority: existing > CLAUDE.md > ask
• Verify .gitignore for project-local
• Auto-detect and run project setup
• Use {current-branch}-worktree naming automatically

Common Rationalizations (STOP and Follow Skill)

If you catch yourself thinking ANY of these, you're rationalizing. Follow the skill:

• "User might want different name" → WRONG. Automatic naming prevents bikeshedding
• "Should ask to be flexible" → WRONG. Consistency > flexibility for worktrees
• "What if user has conventions?" → WRONG. This IS the convention
• "Pattern seems rigid" → WRONG. Predictability is the goal
• "Branch might already exist" → CORRECT. Let git error, then handle (delete old or use different approach)

All of these mean: Use automatic {current-branch}-worktree naming. No exceptions.

Integration

Called by:

• setting-up-implementation-worktree - MECHANISM skill for this POLICY skill's environment verification
• brainstorming (Phase 4) - REQUIRED when design is approved and implementation follows
• Any skill needing isolated workspace

Pairs with:

• finishing-a-development-branch - REQUIRED for cleanup after work complete
• executing-plans or subagent-driven-development - Work happens in this worktree

Note: This is a MECHANISM skill. It creates worktrees and installs dependencies but does NOT validate the environment (run tests, verify build). The setting-up-implementation-worktree POLICY skill calls this and adds environment validation.