Bug Sweep

Bug Sweep — Systematic Codebase Bug Hunt

Sweep the codebase for bug patterns, fix everything AI-fixable in-session, defer human-dependent bugs to the backlog. Not a daily check — use when code churn warrants it. Occupies your context for ~20-40 min; not background work.

Not for: recent-commit review (daily-code-health), architectural debt (weekly-architecture-audit), or a single known bug (just fix it — or /systematic-debugging).

Arguments

$ARGUMENTS is an optional path to scope the sweep; omitted means full codebase. Announce: "I'm running /bug-sweep — systematic bug hunt [scoped to X / across the full codebase]."

Phase 0: Scope and Pattern Selection (YOU do this)

1. bug-sweep-probes detect-stack [path] → language_files, test_dirs, config_files.
2. DOCS_VERIFY — compiled/opinionated stack → true (enables Track C, makes Phase 3.5 mandatory); TS/JS/Python → false. Calibration: wiki.
3. Select patterns from the Pattern Library (end of this doc) per detected stack; universal patterns always apply.
4. Define 3-6 search chunks by directory/system (architecture atlas, else DIRECTORY.md/directory structure).
5. Hot-zone rank: query-completions --since "30d" --where "nature=bugfix" --format json, aggregated by path-prefix — hot chunks dispatch first, chunks with a bugfix completion in the last 7 days deprioritize; both at once is a real conflict, surface it. Record to tasks/scratch/bug-sweep/{run-id}/hot-zone-ranking.md; skip if the query returns nothing.
6. Identify the test runner (Track B).
7. Read state/lessons/ for project-specific patterns to add.
8. Generate run ID (YYYY-MM-DD-HHhMM), create tasks/scratch/bug-sweep/{run-id}/.
9. Output: chunk table with pattern assignments, hot-zone ranking, test runner command.

Pre-Dispatch: Verify Backlog Against Current Code

Run backlog-grind-assemble brief bug-sweep. Empty/all-closed state/bug-backlog/ → straight to Phase 1. Open entries → resolve j-bug-sweep-pre-dispatch-verification-due (re-verify cited items against HEAD before dispatch? — the engine has no opinion here).

If verifying, dispatch one Haiku agent per system: read each cited file:line against HEAD, check

still-open/already-fixed (SHA, or unattributed). Drop already-fixed; record verified-fixed IDs + SHAs to pre-dispatch-already-fixed.md (Phase 4 prunes the backlog from this file).

A concurrent-EM peer can invert a verdict mid-pipeline — check

dispatching verifiers; non-empty means escalate the verifier to Sonnet and re-verify at Phase 1 launch (git log --oneline -- <file> since its read SHA). Detail: wiki.

Before fixing any P0/P1, read the cited code yourself (or via a verifier) — never trust the agent's paraphrase; P0 carries a measured far higher false-positive rate than P2.

Phase 1: Search + Test (dispatch leaf agents, parallel)

Track A1 — Mechanical Pattern Grep (YOU, fast): deterministic grep across all chunks — TODO/FIXME/HACK/XXX/BUG, empty catch/except, language-specific mechanical patterns. <30s; feeds Track A2 as context.

Track A2 — Semantic Analysis (one Sonnet per chunk): the sweep's actual purpose, irreducibly a judgment call. Each agent gets its chunk's file list, patterns, Track A1's results, and hot-zone ranking (cooldown paths noted). Dispatch prompt, verbatim:

Cast a wide net. Report bugs AND code smells — both are worth fixing. Err on the side of reporting — false positives are cheap, missed issues are expensive. Use P0/P1/P2 severity ONLY — do not invent P3, 'info', or 'defer' tiers. A code smell that can be fixed in under 5 minutes is P2, not 'informational'. Write your complete findings to {scratch-path} using the Write tool. Return only a brief summary — the coordinator reads full output from disk.

Per file: review Track A1's grep findings for false positives, run deeper semantic analysis (error handling gaps, null access, resource leaks, logic errors, dead code, race conditions), and for each finding give severity (P0/P1/P2), confidence (HIGH/MEDIUM/LOW), file:line, description, AI-fixable-or-not. Scratch: {chunk-name}-phase1-sonnet.md.

Track B — Test Suite (EM runs; Haiku parses): Tier-U-gated, no implicit grant. Ask the PM using backlog-grind-assemble brief bug-sweep's exact ask text (j-bug-sweep-tier-u-grant) — a grant names the suite/Tier-U as its subject, not adjacent sweep approval. Granted → backlog-grind- assemble apply bug-sweep --decisions-file <path> (path to a file containing {"j-bug-sweep-tier-u-grant":"granted"}; shells to tier-u-grant-cli for you). Declined → apply nothing, skip Track B, report the decline.

Immediately before firing, recheck tier-u-grant-cli check live (exit 0 grants, exit 1 halts). Run the suite via Bash yourself; dispatch one model: "haiku" agent to parse the captured output (never invoke it) into pass/fail/error counts and, per failure, error/file:line/likely source. No suite → report the gap, skip. Scratch: tests-phase1-haiku.md.

Track C — API Documentation Verification (DOCS_VERIFY = true only): dispatch one coordinator:docs-checker per chunk (model: "sonnet"), sidecar path from the dispatch brief. Scans external API references against example-game-repo-docs (UE) or Context7. INCORRECT → P1. UNVERIFIED

• zero RAG hits on a UE-naming symbol → P2 ("possible hallucinated API"). UNVERIFIED from server unavailability → drop. Rationale: wiki. Scratch: {chunk-name}-phase1-docschecker.md.

Scratch verification: before Phase 2, confirm expected scratch files exist —

proceed with what's available on a second failure.

Phase 1.5: Churn-Gated Findings Verification (conditional)

Gate: git rev-list --count <last-sweep-sha>..HEAD -- <chunk-paths> (SHA from state/bug-backlog/.meta.yaml's last_sweep_commit:) > 200; missing meta/key or ≤200 → skip to Phase 2. Rationale: wiki.

Dispatch one Haiku verifier per chunk against its {chunk-name}-phase1-sonnet.md: read the cited file:line for every P0/P1, return still-present/already-fixed (SHA/unattributed)/ pattern-shifted. Write to {chunk-name}-phase1.5-verification.md. Phase 2 considers only still-present; the rest drop out, noted in the Phase 4 report.

Phase 2: Triage (YOU do this)

Read all Phase 1 findings. When DOCS_VERIFY = true, merge Track C's INCORRECT and suspicious UNVERIFIED findings in first.

Categorize (the sweep's other irreducible judgment call) into Fix now (default — clear bug or smell + clear fix), Backlog (only genuinely blocked: human verification, plan session, or intent-ambiguous logic — never "low confidence," never a code smell, never under 10 minutes), or False positive (pattern matched, not a bug). "Needs runtime confirmation" is not itself a reason to backlog when the fix is free and safe (trivially correct by inspection, reverts cleanly, no migration, no user-visible change) — apply it now and note "fix applied; runtime confirmation deferred." Bias toward fixing: same effort to fix as to document, and a code smell is always fixable — never belongs in backlog. Full worked examples: wiki.

Output: "Fix now"/"Backlog" lists grouped by file, cross-agent duplicates merged. Also write phase2-fix-now.json (Phase 4's diff gate consumes it), minimum field file:

[
  {"id": "F-A-03", "file": "src/foo.py", "line": 142, "severity": "P1", "description": "missing threading.Lock on counter"}
]

Phase 3: Fix (dispatch Sonnet executors, parallel)

Dispatch Sonnet executors, grouped by file/system to minimize conflicts. Each receives its finding group, source files, acceptance criteria per fix, and this verify-first contract, verbatim (sweepers anchor on historical bug shapes after heavy churn without it):

Fix the listed bugs. For each fix:

1. Read the cited line range.
2. Determine whether the code is in the buggy state described OR already in the fixed state.
3. If already fixed, report no-op — already in HEAD for that finding and SKIP without editing.
4. If buggy, apply the fix and re-read to verify the edit landed.

Do NOT apply an edit that produces byte-identical content. An Edit that succeeds with no diff is a false-positive finding, not a fix.

Write a brief summary of changes to {scratch-path} using the Write tool. The summary MUST distinguish fixed vs no-op — already in HEAD per finding.

Post-fix: re-run the test suite yourself (same Track B grant, recheck tier-u-grant-cli check live, no second ask). Any newly-failing test → revert that fix, backlog it noting "regression introduced." Skip if Track B was declined/skipped.

Phase 3.5: Post-Fix API Verification (YOU do this)

Mandatory when DOCS_VERIFY = true; recommended whenever fixes touch external library APIs. Get the changed-file set (git diff --name-only); dispatch one coordinator:docs-checker against it (sidecar path from the brief): "verify all external API claims in these modified files; report INCORRECT and suspicious-UNVERIFIED only." No INCORRECT → Phase 4. INCORRECT in a fix → git checkout -- {file} to revert, backlog with the verdict, original bug stays open. UNVERIFIED zero-hit UE-naming pattern → flag in the report, don't block. Reads only changed files — not a re-sweep.

Phase 4: Report and Commit (YOU do this)

0. Mechanical diff gate: bug-sweep-probes verify-diff --fix-now tasks/scratch/bug-sweep/{run-id}/phase2-fix-now.json — non-empty missing means an executor no-op claimed a fix; list as Zero-diff fixes, doesn't block committing real fixes. Rationale: wiki.

1. Commit fixes — never narrate the git sequence, never coordinator-safe-commit (${CLAUDE_PLUGIN_ROOT}/docs/wiki/scoped-safety-commits.md): pass each changed path (git diff --name-only) as a --wave-path to backlog-grind-assemble apply bug-sweep --wave-path <path>... --granularity per-wave --message "bug-sweep: fixed N bugs across M files" — one op, one commit, engine-scoped so a concurrent session's staged files stay untouched. --message must be a single line. It has no -file sibling and does not refuse a newline; the .cmd forwarder truncates a multi-line value at the first LF and the commit lands short, exit 0, reported as done. Detail that won't fit goes in the backlog entries the commit renames, not in a second message line.

2. Prune already-fixed backlog entries (separate, paper-trail commit). Read pre-dispatch-already-fixed.md; per item, stamp status: closed, closed_at:, closed_by: <SHA or unattributed>, git mv to archive/bug-backlog/<YYYY-MM>/, then the same apply op (--wave-path per renamed file, --granularity per-wave, a single-line --message naming each closed ID with its resolving SHA). Skip if nothing was already-fixed.

3. Append genuinely blocked items via coordinator-queue-append --schema bug-backlog --surface <subsystem> --severity P1 --status open --title "<title>" --body-file <path> [--why-file <path>] [--evidence <ref>] (cross-reference state/debt-backlog/ where it overlaps). The prose flags take the -file transport, never inline: a .cmd-forwarded inline value is truncated at the first newline, and these CLIs now refuse a newline-bearing inline rather than land a one-line record. Write/update state/bug-backlog/.meta.yaml (last_sweep_commit:/last_sweep_at:, zero counts too), then the same apply op scoped to state/bug-backlog/.

4. Report to PM, by exception. A clean sweep spends its budget on facts the PM can't read off the commit — per-file:line detail belongs in the commit message, not here.

   ## Bug Sweep Complete
   
   **Found:** [total] findings ([X] fixed, [Y] blocked, [Z] false positives)
   **Fixes applied:** [N] fixed — [one-line characterization]. Full file:line list is in the
   commit message.
   

   Append a line only when its condition holds:

   Line	Include only when
   **Tests run:**	Track B ran and any test failed/errored
   **Zero-diff fixes:**	the diff gate's missing list is non-empty
   **Phase 1.5 verification:**	churn gate tripped — K still-present, L already-fixed, M pattern-shifted
   **Blocked items:**	N ≥ 1 — list each with its "why blocked" reason
   **Docs verification (Phase 3.5):**	DOCS_VERIFY = true and an INCORRECT finding was reverted
   **Track C API sweep:**	DOCS_VERIFY = true and it found INCORRECT/suspicious-UNVERIFIED

   Scope, Patterns applied, and Backlog pruned are never printed — the commits already record them. A clean Track B run, an untripped Phase 1.5 gate, and zero blocked items stay silent too — absence is the signal. Rationale: wiki.

5. Leave scratch in place after commit. tasks/scratch/bug-sweep/{run-id}/ carries file:line citations later consumers may need. Delete at /workstream-complete's self-clean step or an explicit PM cleanup signal, whichever comes first; note the scratch path in the handoff body if the next step is /handoff.

Pattern Library, Cost Profile, Failure Modes

See pipelines/bug-sweep/pattern-library.md for the full pattern catalog (universal + per-language: Python, JS/TS, C++/UE, code smells), the cost profile table, and the full failure-modes matrix.