using-git-worktrees

name	using-git-worktrees
preamble-tier	2
version	1.0.0
description	Create isolated git worktrees for feature work. Use when starting feature work that needs isolation from the current workspace or before executing implementation plans. Smart directory selection and safety verification.
allowed-tools	["Bash","Read","AskUserQuestion"]
announce-action	set up an isolated workspace

Preamble (run first)

# === RKstack Preamble (using-git-worktrees) ===

# Read detection cache (written by session-start via rkstack detect)
if [ -f .rkstack/settings.json ]; then
  cat .rkstack/settings.json
else
  echo "WARNING: .rkstack/settings.json not found — detection cache missing"
fi

# Session-volatile checks (can change mid-session)
_BRANCH=$(git branch --show-current 2>/dev/null || echo "unknown")
_HAS_CLAUDE_MD=$([ -f CLAUDE.md ] && echo "yes" || echo "no")
echo "BRANCH: $_BRANCH"
echo "CLAUDE_MD: $_HAS_CLAUDE_MD"

Use the detection cache and preamble output to adapt your behavior:

• TypeScript/JavaScript — see detection.flowType (web or default). If web: check React/Vue/Svelte patterns, responsive design, component architecture. If default: CLI tools, MCP servers, backend scripts.
• Python — backend/ML/scripts. Check PEP8 conventions, pytest for testing.
• Go — backend/infra. Check error handling patterns, go test.
• Rust — systems. Check ownership patterns, cargo test.
• Java/C# — enterprise. Check build tool (Maven/Gradle/.NET), framework conventions.
• Ruby — web/scripting. Check Gemfile, Rails conventions if present.
• Terraform/HCL — infrastructure as code. Plan before apply, extra caution with state.
• Ansible — configuration management. Check inventory, role conventions, vault usage.
• Docker/Compose — containerized. Check service dependencies, .env patterns.
• justfile — task runner present. Use just commands instead of raw shell.
• mise — tool version manager. Versions are pinned — don't suggest global installs.
• CLAUDE.md exists — read it for project-specific commands and conventions.
• Read detection.stack for what's in the project and detection.stats for scale (files, code, complexity).
• Read detection.repoMode for solo vs collaborative.
• Read detection.services for Supabase and other service integrations.

AskUserQuestion Format

ALWAYS follow this structure for every AskUserQuestion call:

1. Re-ground: State the project, the current branch (use the _BRANCH value from preamble — NOT any branch from conversation history or gitStatus), and the current plan/task. (1-2 sentences)
2. Simplify: Explain the problem in plain English a smart 16-year-old could follow. No raw function names, no internal jargon, no implementation details. Use concrete examples and analogies. Say what it DOES, not what it's called.
3. Recommend: RECOMMENDATION: Choose [X] because [one-line reason] — always prefer the complete option over shortcuts (see Completeness Principle). Include Completeness: X/10 for each option. Calibration: 10 = complete implementation (all edge cases, full coverage), 7 = covers happy path but skips some edges, 3 = shortcut that defers significant work.
4. Options: Lettered options: A) ... B) ... C) ... — when an option involves effort, show both scales: (human: ~X / CC: ~Y)

Assume the user hasn't looked at this window in 20 minutes and doesn't have the code open. If you'd need to read the source to understand your own explanation, it's too complex.

Completeness Principle

AI makes completeness near-free. Always recommend the complete option over shortcuts — the delta is minutes with AI. A "lake" (100% coverage, all edge cases) is boilable; an "ocean" (full rewrite, multi-quarter migration) is not. Boil lakes, flag oceans.

Effort reference — always show both scales:

Task type	Human team	CC + AI	Compression
Boilerplate	2 days	15 min	~100x
Tests	1 day	15 min	~50x
Feature	1 week	30 min	~30x
Bug fix	4 hours	15 min	~20x

Include Completeness: X/10 for each option (10=all edge cases, 7=happy path, 3=shortcut).

Completion Status

When completing a skill workflow, report status using one of:

• DONE — All steps completed successfully. Evidence provided for each claim.
• DONE_WITH_CONCERNS — Completed, but with issues the user should know about. List each concern.
• BLOCKED — Cannot proceed. State what is blocking and what was tried.
• NEEDS_CONTEXT — Missing information required to continue. State exactly what you need.

Escalation

It is always OK to stop and say "this is too hard for me" or "I'm not confident in this result."

Bad work is worse than no work. You will not be penalized for escalating.

• If you have attempted a task 3 times without success, STOP and escalate.
• If you are uncertain about a security-sensitive change, STOP and escalate.
• If the scope of work exceeds what you can verify, STOP and escalate.

Escalation format:

STATUS: BLOCKED | NEEDS_CONTEXT
REASON: [1-2 sentences]
ATTEMPTED: [what you tried]
RECOMMENDATION: [what the user should do next]

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/rkstack/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:

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/rkstack/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
case $LOCATION in
  .worktrees|worktrees)
    path="$LOCATION/$BRANCH_NAME"
    ;;
  ~/.config/rkstack/worktrees/*)
    path="~/.config/rkstack/worktrees/$project/$BRANCH_NAME"
    ;;
esac

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

3. Run Project Setup

Auto-detect and run appropriate setup. Read CLAUDE.md first for project-specific setup commands. If CLAUDE.md specifies setup commands, use those. Otherwise auto-detect from project files:

# 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. Read CLAUDE.md for the project-specific test command. If not specified, auto-detect:

# Examples - use project-appropriate command from CLAUDE.md
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
.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
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: Read CLAUDE.md first, then 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/you/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 clean test baseline

Integration

Called by: any skill needing isolation — typically before writing-plans or executing-plans

Pairs with:

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