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."

When to Use

• Starting feature work that needs isolation from current changes in the working tree
• Executing an implementation plan that spans multiple tasks and branches
• Working on multiple branches of the same repo simultaneously without stash churn

NOT when: the feature is small enough to complete in one session on the current branch.

Step 0: Detect Existing Isolation

Before creating anything:

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)
git rev-parse --show-superproject-working-tree 2>/dev/null  # prints a path → submodule, treat as normal repo

• GIT_DIR != GIT_COMMON and not a submodule → already in a linked worktree. Do NOT create another; skip to Run Project Setup. Report the path and branch, or "detached HEAD, externally managed — branch needed at finish".
• Otherwise (normal checkout): honor any declared worktree preference; if none, ask consent first ("Set up an isolated worktree? It protects your current branch."). Declined → work in place, skip to Run Project Setup.

Step 1: Prefer the Harness's Native Tool

If you have a native worktree tool (e.g. EnterWorktree, WorktreeCreate, a /worktree command, a --worktree flag), use it and skip to Run Project Setup. git worktree add beside a native tool creates state the harness cannot see or clean up. Only with no native tool, continue below.

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 directory is ignored before creating worktree:

# Check if directory is ignored (respects local, global, and system gitignore)
git check-ignore -q .worktrees 2>/dev/null || git check-ignore -q worktrees 2>/dev/null

If NOT ignored:

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 Project Name

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

2. Create Worktree

# Determine full path
global_root="$HOME/.config/superpowers/worktrees"
case "$LOCATION" in
  .worktrees|worktrees)
    path="$PWD/$LOCATION/$BRANCH_NAME"
    ;;
  "$global_root"|"$global_root"/*|"~/.config/superpowers/worktrees"|"~/.config/superpowers/worktrees/"*)
    path="$global_root/$project/$BRANCH_NAME"
    ;;
  *)
    printf 'Unsupported worktree location: %s\n' "$LOCATION" >&2
    exit 1
    ;;
esac

# Stop before setup if creation or directory entry fails.
git worktree add "$path" -b "$BRANCH_NAME" || exit
cd "$path" || exit

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. Verify Clean Baseline

Run tests to ensure worktree starts clean:

# Examples - 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.

5. Report Location

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

Quick Reference

Common Mistakes

Red Flags

Never:

• Create a worktree while already inside one, or beside a native worktree tool
• Create worktree without verifying it's ignored (project-local)
• Skip baseline test verification
• Proceed with failing tests without asking
• Assume directory location when ambiguous
• Skip CLAUDE.md check

Always:

• Follow directory priority: existing > CLAUDE.md > ask
• Verify directory is ignored for project-local
• Auto-detect and run project setup
• Verify clean test baseline

Integration

Called by:

• brainstorming (Phase 4) - REQUIRED when design is approved and implementation follows
• subagent-driven-development - REQUIRED before executing any tasks
• executing-plans - REQUIRED before executing any tasks
• Any skill needing isolated workspace

Pairs with:

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