Prune Git Worktrees

When the user asks Copilot Chat to prune, clean up, or remove stale git worktrees, follow this protocol. The same logic ships as a Claude skill and a Codex skill — VS Code Copilot Chat must produce equivalent behavior.

Required preconditions

Before suggesting any worktree removal:

1. The user has authenticated gh (run gh auth status).
2. The repo has an origin remote pointing at GitHub.
3. The user has confirmed the default branch for the repo (main for most, develop for gitflow repos like otc-awesome-llm).

Decision algorithm

For each entry returned by git worktree list --porcelain:

1. Skip and KEEP if any of:
   • Path equals the main/bare clone root.
   • Worktree is detached HEAD.
   • git status --porcelain is non-empty (uncommitted changes).
   • git rev-list --count origin/<branch>..HEAD is non-zero (unpushed commits).
2. Mark PRUNE if any of:
   • git rev-parse --verify --quiet origin/<branch> fails (remote branch deleted).
   • gh pr list --repo <owner>/<repo> --state merged --head <branch> --limit 1 returns a non-empty array.
   • git merge-base --is-ancestor <branch-tip> origin/<default> succeeds.
3. Otherwise KEEP and report "not merged".

Mutating actions (only after explicit user approval)

git worktree remove <path>
git branch -D <branch>     # only after the worktree remove succeeds

Never use git worktree remove --force to bypass a dirty-state guard.

Recommended invocation

The canonical Python implementation lives in this repo at shared/skills/prune-worktrees/scripts/prune_worktrees.py. Prefer running it over hand-rolling the logic:

# Always dry-run first
python3 shared/skills/prune-worktrees/scripts/prune_worktrees.py \
  /path/to/repo --dry-run

# Apply when the user approves the dry-run output
python3 shared/skills/prune-worktrees/scripts/prune_worktrees.py \
  /path/to/repo --default main

Hard rules

• Do NOT delete a branch whose worktree still exists — git worktree remove must succeed first.
• Do NOT run across multiple repos in a single command — one repo per call.
• Do NOT suggest this skill in a repo without an origin remote on GitHub.
• Surface the per-entry decisions to the user verbatim; do not summarize away the audit trail.