Duck Sweep

---
name: duck-sweep
description: Clean out stale branches, worktrees, checkouts, scratch directories, and ignore rules; the pond stays clean. Use when the user asks for repository cleanup across one or more repos, or when stale worktrees and temporary artifacts have accumulated after merged work.
---

# Duck Sweep

Multi-repo cleanup with a hard rule: **verify merged before delete, and keep nothing "just in
case"** — unmerged work gets an explicit merge-or-delete decision, not a reprieve. One
preservation invariant covers every deletion path: an entry marked **keep** relocates to its
durable home and is verified there before its container is removed.

Follow the user’s language unless they ask otherwise. Keep commands, paths, identifiers,
quoted errors and machine-readable verdicts unchanged; the duck asks for evidence in any language.

## Sweep per repo

1. Inventory: `git worktree list`, `git branch -vv`, `git fetch --prune` first so remote state is
   current. Use absolute paths; don't cd back and forth. An unreachable remote or an unreadable
   worktree is recorded and the sweep carries on around it.
2. Classify by one invariant: **delete only what is provably preserved elsewhere**.
   - **Preserved** — the branch's commits are reachable from `origin/<default>`
     (`git branch --merged origin/<default>`, then `-d`, never `-D`; `-d` alone checks
     HEAD-or-upstream, a narrower promise than its name). These outlive their ref. Delete.
   - **Preserved by record** — squash-merged, rebased, or cherry-picked, *and* the project's
     outcome record names the landed SHA for this branch (`duck-land` writes it there for exactly
     this reason). The record is evidence the objects cannot supply. Confirm the named SHA is on
     `origin/<default>`, then delete.
   - **Not preserved** — squash-merged, rebased, or cherry-picked with **no such record**: the
     default branch holds an equivalent *new* commit, never these objects, and no merge metadata
     recovers the link — PR records, `git cherry`, tree diffs, and revert greps can each produce a
     false positive, and a false positive here is destroyed work. Do not build a cleverer
     classifier; route to a decision instead.
   - **Unproven** → the Unmerged path: open the work item, decide merge-or-delete on its state,
     record the decision, then `-D`.
3. Delete — **but check the worktree for untracked and ignored files first**: `git status --short
   --untracked-files=all --ignored`. Plain `git status` hides ignored files, so `git worktree
   remove` exits 0 and takes the `.env`, local config, or credentials living there with it. Any `??`
   or `!!` entry gets an explicit keep-or-delete decision before removal — those files exist in
   exactly one place by definition; the preservation invariant applies, so **unknown means keep, and
   only the owner may decide to delete one**. Uncommitted work is the case with no second copy to
   recover from, which is why this decision is never the doer's however obvious it looks; queue it
   via `duck-decide` and keep the file meanwhile. Then — only once nothing in the worktree remains
   marked keep — `git worktree remove <path>`, `git branch -d <branch>` (`-D` only on the Unmerged
   path, against its recorded decision), and `git worktree prune` for leftovers.
4. Scratch dirs: hunt ad-hoc temp dirs outside the sanctioned scratchpad (e.g. `~/<repo>-tmp*`,
   `/tmp/<repo>*`, stray review-tmp dirs; the sanctioned scratchpad itself is disposable by design
   and never swept per-file). A non-git dir has no merge evidence, so inventory every entry
   including dotfiles (`ls -laR`), decide keep-or-delete per entry — unknown means keep. The
   preservation invariant applies; `rm -rf` the dir only when nothing in it remains marked keep.
5. `.gitignore` audit: worktree dirs (`.worktrees/`), build output, and local-config paths present
   and ignored; `git status --ignored` sanity check.

## Report shape

Per repo: deleted (with merge evidence), kept (with the work item justifying it), decisions made.
A deletion without stated merge evidence is not done.

## Common mistakes

- Cleaning only the repo you're in when the setup is multi-repo — sweep all sibling repos asked for.