using-git-worktrees

name	using-git-worktrees
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.

Higher-level rule: If the repo already has a native worktree workflow (just wt, project scripts, AGENTS/CLAUDE instructions, tmux window integration), use that instead of raw git worktree add.

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

Workflow Selection Process

Follow this priority order:

1. Check For Repo-Native Worktree Commands

Look for project-specific worktree workflows before deciding any path:

just --list 2>/dev/null | rg '^\s*wt\s' || true
rg -n 'just wt|worktree' AGENTS.md CLAUDE.md README* justfile justfile.common 2>/dev/null || true

If the repo provides a worktree workflow: use it.

Examples:

• just wt new <name>
• project scripts that create worktrees under /workspaces/...
• repo docs that explicitly say where worktrees belong

Why: native workflows may also create tmux windows, assign ports, or enforce cleanup/land conventions. Raw git worktree add would bypass those integrations.

2. Check Repo Policy Files

Before picking any fallback directory, read repo instructions:

rg -n 'worktree' AGENTS.md CLAUDE.md 2>/dev/null || true

If policy says worktrees live under /workspaces/: obey that and do not use ~/.config/superpowers/worktrees/....

Container rule: inside devcontainers or similar containerized workspaces, prefer /workspaces/... over ~/.config/... even when using the generic fallback. Home-directory paths may disappear on container recreate.

Directory Selection Process

Follow this priority order:

1. Check Existing Project-Local 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 Repo Policy For /workspaces/... Preference

rg -n 'worktree|/workspaces/' AGENTS.md CLAUDE.md 2>/dev/null

If /workspaces/... is specified: use a path under /workspaces/ without asking.

Suggested generic fallback:

project=$(basename "$(git rev-parse --show-toplevel)")
path="/workspaces/.worktrees/$project/$BRANCH_NAME"

3. Choose A Default Non-Interactively

If no directory exists and no repo policy specifies a location, choose a default without asking:

• If /workspaces exists, use /workspaces/.worktrees/<project-name>/
• Otherwise use .worktrees/ and verify it is ignored
• Use ~/.config/superpowers/worktrees/... only as a last-resort host fallback

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 /workspaces/... Fallback Directories

No .gitignore verification needed when the directory is outside the repo.

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

Use only as a last resort on host systems without a repo-local or /workspaces/... convention. Avoid it inside devcontainers.

Creation Steps

1. Detect Project Name

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

2. Prefer Repo-Native Creation

If the repo supports a native command, use it:

just wt new "$BRANCH_NAME"

Then discover the resulting path:

git worktree list

3. Generic Create Worktree

# Choose LOCATION from the earlier discovery steps before entering this branch.
# Determine full path
case $LOCATION in
  .worktrees|worktrees)
    path="$repo_root/$LOCATION/$BRANCH_NAME"
    ;;
  /workspaces/*)
    path="/workspaces/.worktrees/$project/$BRANCH_NAME"
    ;;
  ~/.config/superpowers/worktrees/*)
    path="$HOME/.config/superpowers/worktrees/$project/$BRANCH_NAME"
    ;;
esac

# Create worktree with new branch
git -C "$repo_root" worktree add "$path" -b "$BRANCH_NAME"
cd "$path"

4. Run Project Setup

Auto-detect and run appropriate setup:

# Project-native setup first
if [ -f justfile ] && just --list 2>/dev/null | rg '^\s*install\s'; then just install; fi

# Python
if [ -f uv.lock ]; then uv sync; fi
if [ -f package.json ]; then npm install; fi

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

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

5. 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.

6. Report Location

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

Quick Reference

Situation	Action
Repo has just wt or equivalent	Use it instead of raw git worktree add
AGENTS/CLAUDE says /workspaces/	Use /workspaces/...
.worktrees/ exists	Use it (verify ignored)
worktrees/ exists	Use it (verify ignored)
Both exist	Use .worktrees/
Neither exists	Check repo policy → choose default automatically
Directory not ignored	Add to .gitignore + commit
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: repo-native workflow > repo policy > existing dirs > ask

Asking the user when a safe default exists

• Problem: Conflicts with non-interactive/autonomous agent operation
• Fix: Prefer repo-native workflow, then /workspaces/..., then .worktrees/

Using ~/.config/superpowers/worktrees inside a devcontainer

• Problem: Worktrees may disappear on container recreate and bypass repo-native integrations.
• Fix: Prefer just wt or /workspaces/...

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:

• Bypass a repo-native worktree workflow like just wt
• 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 AGENTS/CLAUDE repo-policy check

Always:

• Prefer repo-native worktree commands when present
• Follow priority: repo-native workflow > repo policy > existing dirs > 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