using-git-worktree

name	using-git-worktree
description	Use when starting feature work that needs isolation from current workspace or before executing implementation plans - creates isolated git worktrees with smart directory selection and safety verification

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."

Pre-Flight: Already Isolated?

Before doing anything else, check whether the current session is already inside a worktree or on a non-main branch:

# Already inside a worktree?
if [ "$(git rev-parse --git-common-dir)" != "$(git rev-parse --git-dir)" ]; then
  echo "Already inside a worktree ($(pwd)) — skipping creation."
  # Report the existing worktree location and exit the skill
fi

# On a non-main feature branch? (skip if detached HEAD — that's not isolation)
current_branch=$(git rev-parse --abbrev-ref HEAD)
main_branch=$(git symbolic-ref refs/remotes/origin/HEAD 2>/dev/null | sed 's|refs/remotes/origin/||')
# Fallback: if origin/HEAD is not set, sed exits 0 with empty output, so default explicitly
main_branch="${main_branch:-main}"
if [ "$current_branch" != "HEAD" ] \
   && [ "$current_branch" != "$main_branch" ] \
   && [ "$current_branch" != "main" ] \
   && [ "$current_branch" != "master" ]; then
  echo "Already on feature branch '$current_branch' — skipping worktree creation."
  # Report the current branch and exit the skill
fi

If either check is true: Report that isolation already exists and skip the rest of this skill. Do not ask the user or create a new worktree.

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, use .worktrees/ (project-local, hidden).

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.

Creation Steps

1. Detect Project Name

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

2. Choose Base Branch

Detect the current branch:

current_branch=$(git rev-parse --abbrev-ref HEAD)
main_branch=$(git symbolic-ref refs/remotes/origin/HEAD 2>/dev/null | sed 's|refs/remotes/origin/||' || echo "main")

If on main/master: Skip this step — the worktree will branch from the current HEAD.

If on a feature branch: Ask the user:

You're currently on '<current_branch>'. Which branch should the worktree start from?

1. Current branch (<current_branch>)
2. <main_branch> (main branch)
3. Other (specify)

In either case, make sure the chosen branch is up to date with the remote. If not, pull/rebase it first. This will ensure the worktree is based on the latest changes and avoid conflicts.

Use the chosen branch as the base for git worktree add:

# Branch from chosen base
git worktree add "$path" -b "$NEW_BRANCH_NAME" "$BASE_BRANCH"

3. Create Worktree

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

# Create worktree with new branch from chosen base
git worktree add "$path" -b "$BRANCH_NAME" "$BASE_BRANCH"
cd "$path"

Note: In agent harnesses where each shell call is isolated, cd in one call does not affect the next. Use absolute paths for file tools, or prefix bash commands with cd "/absolute/path/to/worktree" && ….

3. Run Project Setup

Auto-detect and run appropriate setup:

# JVM / Gradle
if [ -f gradlew ]; then ./gradlew classes; fi

# 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

Situation	Action
Already inside a worktree	Skip — report existing worktree and exit skill
Already on a feature branch	Skip — report current branch and exit skill
.worktrees/ exists	Use it (verify ignored)
worktrees/ exists	Use it (verify ignored)
Both exist	Use .worktrees/
Neither exists	Check CLAUDE.md → Ask user
Directory not ignored	Add to .gitignore + commit
On main/master	Branch from current HEAD without asking
On feature branch	Ask: current branch / main / other
Tests fail during baseline	Report failures + ask
No package.json/Cargo.toml	Skip dependency install

Common Mistakes

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 > CLAUDE.md > ask

Proceeding with failing tests

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

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.

[Check .worktrees/ - exists]
[Verify ignored - git check-ignore confirms .worktrees/ is ignored]
[Create worktree: git worktree add .worktrees/auth -b feature/auth]
[Run npm install]
[Run npm test - 47 passing]

Worktree ready at /Users/jesse/myproject/.worktrees/auth
Tests passing (47 tests, 0 failures)
Ready to implement auth feature

Red Flags

Never:

• 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 a clean test baseline

Gradle in Worktrees

When working in a worktree, verify ./gradlew test or ./gradlew check from the worktree path before pushing. Gradle wrapper and cache paths are usually worktree-local.

Cleanup and Failure Recovery

After a branch is merged or abandoned, clean up from the main checkout, not from inside the worktree being removed:

cd /absolute/path/to/main/checkout && git worktree list --porcelain
cd /absolute/path/to/main/checkout && git worktree remove /absolute/path/to/worktree
cd /absolute/path/to/main/checkout && git branch -D <branch-name>

If cleanup fails, diagnose the failure before retrying:

Failure	Likely cause	Recovery
fatal: '<path>' is not a working tree	Git no longer has the path registered, but the directory still exists	From the main checkout, confirm git worktree list --porcelain does not list it, then remove the stale directory (rm -rf <path>)
'<path>' contains modified or untracked files	The worktree still has local changes	Inspect with git -C <path> status --short; only use git worktree remove --force <path> if those changes are intentionally disposable
cannot delete branch ... checked out at <path>	The branch is still attached to a registered worktree	Remove the worktree first, then delete the branch from the main checkout
Follow-up shell commands fail with spawn bash ENOENT or similar	The agent/session was still anchored in the directory that was just deleted	Use a fresh command that starts with cd /absolute/path/to/main/checkout && ...; if the harness remains stuck, report that the stale directory was removed and ask the user to start the next task from the main checkout

Never run cleanup commands from inside the worktree you are deleting. Prefer explicit main-checkout commands for every cleanup step.

Integration

Called by:

• Any skill needing isolated workspace