superpowers/skills/using-git-worktrees/SKILL.md

name, description

name	description
using-git-worktrees	Use when starting feature work that needs isolation from current workspace or before executing implementation plans - ensures an isolated workspace exists via native tools or git worktree fallback

Using Git Worktrees

Overview

Ensure work happens in an isolated workspace. Prefer your platform's native worktree tools. Fall back to manual git worktrees only when no native tool is available.

Core principle: Detect existing isolation first. Then use native tools. Then fall back to git. Never fight the harness.

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

Step 0: Detect Existing Isolation

Before creating anything, check if you are already in an isolated workspace.

GIT_DIR=$(cd "$(git rev-parse --git-dir)" 2>/dev/null && pwd -P)
GIT_COMMON=$(cd "$(git rev-parse --git-common-dir)" 2>/dev/null && pwd -P)
BRANCH=$(git branch --show-current)

Submodule guard: GIT_DIR != GIT_COMMON is also true inside git submodules. Before concluding "already in a worktree," verify you are not in a submodule:

# If this returns a path, you're in a submodule, not a worktree — treat as normal repo
git rev-parse --show-superproject-working-tree 2>/dev/null

If GIT_DIR != GIT_COMMON (and not a submodule): You are already in a linked worktree. Skip to Step 3 (Project Setup). Do NOT create another worktree.

Report with branch state:

• On a branch: "Already in isolated workspace at <path> on branch <name>."
• Detached HEAD: "Already in isolated workspace at <path> (detached HEAD, externally managed). Branch creation needed at finish time."

If GIT_DIR == GIT_COMMON (or in a submodule): You are in a normal repo checkout. Ask for consent before creating a workspace:

"Would you like me to set up an isolated worktree? This protects your current branch from changes. (y/n)"

If yes, proceed to Step 1. If no, work in place — skip to Step 3 with no worktree.

Step 1: Create Isolated Workspace

You have two mechanisms. Try them in this order.

1a. Native Worktree Tools (preferred — STOP HERE if available)

The user has asked for an isolated workspace (Step 0 consent). Check your available tools — do you have EnterWorktree, WorktreeCreate, a /worktree command, or a --worktree flag? If YES: the user's consent to create a worktree is your authorization to use it. Use it now and skip to Step 3.

Native tools handle directory placement, branch creation, and cleanup automatically. Using git worktree add when you have a native tool creates phantom state — your harness can't see or manage worktrees it didn't create, and cleanup becomes impossible.

Even if .worktrees/ already exists, even under time pressure, even if git worktree add feels faster — use your native tool. There are no exceptions.

Only proceed to Step 1b if you have confirmed you have NO native worktree/isolation tool.

1b. Git Worktree Fallback

Only use this if Step 1a does not apply — you have no native worktree tool available. Create a worktree manually using git.

Directory Selection

Follow this priority order:

1. Check existing directories:

   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 for existing global directory:

   project=$(basename "$(git rev-parse --show-toplevel)")
   ls -d ~/.config/superpowers/worktrees/$project 2>/dev/null
   

   If found, use it (backward compatibility with legacy global path).

3. Check your project's agent instruction file (CLAUDE.md, GEMINI.md, AGENTS.md, .cursorrules, or equivalent) for a worktree directory preference. If specified, use it without asking.

4. Default to .worktrees/.

Safety Verification (project-local directories only)

MUST verify directory is ignored before creating worktree:

git check-ignore -q .worktrees 2>/dev/null || git check-ignore -q worktrees 2>/dev/null

If NOT ignored: Add to .gitignore, commit the change, then proceed.

Why critical: Prevents accidentally committing worktree contents to repository.

Global directories (~/.config/superpowers/worktrees/) need no verification.

Create the Worktree

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

# Determine path based on chosen location
# For project-local: path="$LOCATION/$BRANCH_NAME"
# For global: path="~/.config/superpowers/worktrees/$project/$BRANCH_NAME"

git worktree add "$path" -b "$BRANCH_NAME"
cd "$path"

Hooks Awareness

Git worktrees do not inherit the parent repo's hooks directory. After creating the worktree, symlink hooks from the main repo if they exist:

MAIN_ROOT=$(git -C "$(git rev-parse --git-common-dir)/.." rev-parse --show-toplevel)
if [ -d "$MAIN_ROOT/.git/hooks" ]; then
    ln -sf "$MAIN_ROOT/.git/hooks" "$path/.git/hooks"
fi

This prevents pre-commit checks, linters, and other hooks from silently stopping when work moves to a worktree.

Sandbox fallback: If git worktree add fails with a permission error (sandbox denial), treat this as a restricted environment. Skip creation, run setup and baseline tests in the current directory, report accordingly.

Step 3: 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

Step 4: Verify Clean Baseline

Run tests to ensure workspace starts clean:

# Use project-appropriate command
npm test / cargo test / pytest / go test ./...

If tests fail: Report failures, ask whether to proceed or investigate.

If tests pass: Report ready.

Report

Worktree ready at <full-path>
Tests passing (<N> tests, 0 failures)
Ready to implement <feature-name>

Quick Reference

Situation	Action
Already in linked worktree	Skip creation (Step 0)
In a submodule	Treat as normal repo (Step 0 guard)
Native worktree tool available	Use it (Step 1a)
No native tool	Git worktree fallback (Step 1b)
.worktrees/ exists	Use it (verify ignored)
worktrees/ exists	Use it (verify ignored)
Both exist	Use .worktrees/
Neither exists	Check instruction file, then default .worktrees/
Global path exists	Use it (backward compat)
Directory not ignored	Add to .gitignore + commit
Permission error on create	Sandbox fallback, work in place
Tests fail during baseline	Report failures + ask
No package.json/Cargo.toml	Skip dependency install

Common Mistakes

Fighting the harness

• Problem: Using git worktree add when the platform already provides isolation
• Fix: Step 0 detects existing isolation. Step 1a defers to native tools.

Skipping detection

• Problem: Creating a nested worktree inside an existing one
• Fix: Always run Step 0 before creating anything

Skipping ignore verification

• Problem: Worktree contents get tracked, pollute git status
• Fix: Always use git check-ignore before creating project-local worktree

Assuming directory location

• Problem: Creates inconsistency, violates project conventions
• Fix: Follow priority: existing > global legacy > instruction file > default

Proceeding with failing tests

• Problem: Can't distinguish new bugs from pre-existing issues
• Fix: Report failures, get explicit permission to proceed

Red Flags

Never:

• Create a worktree when Step 0 detects existing isolation
• Use git worktree add when you have a native worktree tool (e.g., EnterWorktree). This is the #1 mistake — if you have it, use it.
• Skip Step 1a by jumping straight to Step 1b's git commands
• Create worktree without verifying it's ignored (project-local)
• Skip baseline test verification
• Proceed with failing tests without asking

Always:

• Run Step 0 detection first
• Prefer native tools over git fallback
• Follow directory priority: existing > global legacy > instruction file > default
• Verify directory is ignored for project-local
• Auto-detect and run project setup
• Verify clean test baseline
• Symlink hooks after creating worktree via 1b

Integration

Called by:

• subagent-driven-development - Ensures isolated workspace (creates one or verifies existing)
• executing-plans - Ensures isolated workspace (creates one or verifies existing)
• Any skill needing isolated workspace

Pairs with:

• finishing-a-development-branch - REQUIRED for cleanup after work complete