Using Git Worktrees

Using Git Worktrees

Use This Skill

• Need to start a new task without polluting the current workspace.
• Need to maintain multiple branches in parallel.
• Preparing to execute a large implementation plan or experimental changes.
• The current workspace has uncommitted changes, making it unsuitable for direct branch switching.

Do Not Use

• Just reading code or making very small edits.
• The repository does not use git.
• The user explicitly requests to operate in the current workspace.
• You do not intend to create an independent branch or directory.

Execution Protocol

1. Pre-creation Checks

Confirm Repository Root:

$repoRoot = git rev-parse --show-toplevel

Check if Local Directory is Ignored: If using a directory inside the repository, check if it's ignored:

git check-ignore .worktrees
git check-ignore worktrees

If the local worktree directory is not ignored:

• Add it to .gitignore first.
• Explicitly state this is to prevent worktree contents from polluting the repository state.
• Unless explicitly requested by the user, do not commit these auxiliary changes casually.

Confirm Baseline is Suitable for Forking: Confirm at least:

• The current repository state is readable.
• The base branch exists.
• The new branch name is clear.

2. Determine Target Path

Determine the worktree root directory in this order:

1. Existing .worktrees\ in the repository.
2. Existing worktrees\ in the repository.
3. Location explicitly specified in the repository rules.
4. Confirm with the user.

PowerShell check example:

if (Test-Path ".worktrees") { ".worktrees" }
elseif (Test-Path "worktrees") { "worktrees" }

If a global directory is needed, prefer Windows-accessible paths, e.g.: %USERPROFILE%\worktrees\<project-name>\

Example path calculation:

$branchName = "feature/auth"
$worktreeRoot = ".worktrees"
$worktreePath = Join-Path $worktreeRoot "auth"

3. Create Worktree

git worktree add "$worktreePath" -b "$branchName"

4. Minimal Initialization

Enter the worktree and perform minimal initialization based on the project type. Do not blindly run install commands for all ecosystems.

Common examples:

if (Test-Path (Join-Path $worktreePath "package.json")) {
  npm install
}

if (Test-Path (Join-Path $worktreePath "pyproject.toml")) {
  python -m pip install -e .
}

5. Verify Baseline

Run only the minimal validation to prove "the worktree is ready for development", e.g.:

• Project dependencies installed successfully.
• Key tests can run.
• Lint or type checking can at least start.

If the baseline fails, report it first; do not proceed to implementation with a failing state.

Trae / Windows Conventions

• Use PowerShell-compatible commands on a Windows host.
• Always quote paths when they contain spaces.
• If modifying .gitignore, creating directories, or deleting worktrees, these are explicit actions; do not do them silently.
• If the directory location is ambiguous, ask the user first; do not assume.

Common Errors

• Not checking if the local directory is ignored.
• Hardcoding Unix-style paths.
• Creating the worktree without confirming the branch name.
• Continuing development even if the baseline fails.
• Running a bunch of unnecessary installations or full test suites upfront.

Failure Handling

• Git not installed: Run git --version. If Git is unavailable, stop and report that git worktree cannot be used. Suggest installing Git or proceeding without worktrees.
• Not a Git repository: Stop and report that git worktree cannot be used in the current directory.
• Target path unclear or risky: Ask the user before creating directories or changing .gitignore.
• Branch already exists or conflicts: Report the branch conflict and suggest an alternative branch name.
• Worktree creation fails: Show the git error and do not continue with initialization.
• Baseline validation fails: Report the failing check and keep the worktree in a blocked state instead of proceeding.

Output Contract

After the worktree is created, state at least:

• Worktree path.
• Branch name.
• Whether initialization is complete.
• Which baseline validations were run.
• Whether there are unresolved blockers.

Integration

• executing-plans: Execute a plan after isolating the workspace.
• subagent-driven-development: Advance tasks within the isolated environment.
• finishing-a-development-branch: Decide how to merge, keep, or clean up after work is done.