using-git-worktrees

# Using Git Worktrees

## Overview

Create isolated workspaces sharing the same repository for parallel branch work. Follow systematic directory selection and safety verification to ensure reliable isolation.

**Violating the letter of the rules is violating the spirit of the rules.** Skipping safety verification "just this once" or assuming directory locations are the most common causes of worktree problems.

## When to Use

- Starting feature work requiring isolation from current workspace
- Working on multiple branches simultaneously
- Executing implementation plans in a clean environment (pairs with `humaninloop:plan`)
- Testing changes without affecting the main working directory
- Parallel code review while continuing development

## When NOT to Use

- **Single-branch workflows**: No need for isolation when working linearly
- **Quick fixes on current branch**: Worktrees add overhead for simple changes
- **Non-git repositories**: Worktrees are git-specific
- **Temporary experiments**: A simple branch may suffice
- **When disk space is constrained**: Each worktree duplicates working files

## Red Flags - STOP and Restart Properly

If any of these thoughts arise, STOP immediately:

- "The directory is probably already ignored"
- "I know where worktrees go in this project"
- "Tests are slow, I'll skip baseline verification"
- "This is a simple project, safety checks are overkill"
- "User wants to start quickly, I'll verify later"
- "I've done this before, I can skip the priority order"

**All of these mean:** Rationalization is occurring. Restart with proper process.

## Common Rationalizations

| Excuse | Reality |
|--------|---------|
| "Directory is probably ignored" | Probably =/= verified. One `git check-ignore` command takes seconds. Always verify. |
| "I know where worktrees go here" | Knowledge =/= following process. Check existing directories, then CLAUDE.md, then ask. |
| "Tests are slow" | Slow tests =/= skip tests. Baseline verification prevents hours