Files
boocode/data/skills/mattpocock/diagnosing-bugs/SKILL.md
indifferentketchup 0fa46cd06c v1.13.12: skills audit + token-tracking fix + codecontext + cap50 + UI cleanups
Multi-topic batch. The big-ticket item is the skills audit; the rest are
smaller patches that compounded during the audit work.

## Skills audit (rules→recipes split)

Vendored all 26 skills from /home/samkintop/opt/skills/ into data/skills/
(the boocode-repo-local skill library — see docker-compose change below).
Audited via 5 parallel Claude Code agent-teams running the
mgechev/skills-best-practices 4-step protocol (Discovery → Logic → Edge
Case → self-Architecture-Refinement) per skill, ~2 min wall-clock vs the
~3.7-hour serial estimate.

Result: 14 skills surviving (renamed to gerund form, frontmatter matched),
11 deleted (duplicates, BooCode-irrelevant patterns, Claude-already-does-
natively), 1 migrated to BOOCHAT.md/BOOCODER.md as an always-true rule
(verification-before-completion). Each surviving skill had its description
refined to fix specific trigger gaps surfaced by the protocol — 4
real-bug findings landed (dead refs, stale tags, broken sub-file
references in the original vendored content).

Audit decisions documented in openspec/changes/v1.13.12-skills-audit/
audit-notes.md. Convention codified in BOOCHAT.md/BOOCODER.md "rules vs
recipes" sections — future workflow rules go to those files (100%
present), recipes stay in data/skills/ (~6% invoke rate in multi-turn
per the Codeminer42 measurement).

## Token tracking + stale-stream banner fix (same root cause)

ws-frames.ts IsoTimestamp was z.string().min(1) but postgres returns
timestamp columns as JS Date objects. Every message_complete /
session_updated / chat_updated frame was failing the v1.13.11 Zod gate
and being silently dropped. Symptoms: token tracking blank in the UI
(no usage frames landed); the 60s no-token-activity timer tripped the
stale-stream banner because the frontend's local message state never
saw status='streaming' flip to 'complete'.

Fix: z.preprocess(v => v instanceof Date ? v.toISOString() : v,
z.string().min(1)) applied to the IsoTimestamp primitive. Centralized,
no publisher changes, works identically server + web (the parity test
still passes).

## Codecontext .codecontextignore auto-install

services/codecontext_client.ts now copies the
codecontext/.codecontextignore.template into any project's root on the
first call to that project if no .codecontextignore exists. One file
written per project, idempotent (in-memory Set guard + access-check),
silent fallback on read-only project. Stops the upstream empty-source-
file parser crash on foreign projects' node_modules — previously
required manually copying the template per project.

## Tool-call budget cap 30 → 50

services/inference/budget.ts: BUDGET_READ_ONLY and BUDGET_NO_AGENT
bumped to 50 (from 30). BUDGET_NON_READ_ONLY stays at 10 (no write
tools landed yet). Real recon sessions were hitting 30 with ~3 turns
wasted on codecontext parse failures; legitimate need was ~27, and
Architect-class system overviews want deeper recon. Headroom of 20
absorbs failure-retry turns without changing the safety floor — the
doom-loop guard (3 identical calls → abort) catches the actual
failure mode this cap was guarding against.

v1.14 (Phase C outer agent loop) will supersede this via per-agent
agent.steps. Throwaway-ish patch but unblocks deeper recon today.

## UI cleanups

- ChatPane queued-message dropdown removed. Each queued message now
  has three buttons: edit (pop back into ChatInput via sendToChat
  event), force-send (was the dropdown's only useful action), and
  cancel. Default behavior (send when streaming completes) needs no
  UI — it's the implicit do-nothing path.
- ChatThroughput removed from desktop tab strip (ChatTabBar.tsx).
  Mobile tab switcher still shows it.

## Plumbing

- .gitignore: data/* + !data/AGENTS.md + !data/skills/ negation
  patterns so the vendored skill library + agent registry become
  git-tracked while session DB state stays out.
- docker-compose.yml: removed /opt/skills:/data/skills override
  mount. Skills now live in the boocode repo at data/skills/,
  auditable per-batch. The host-level /opt/skills/ is preserved
  untouched for any other tools that read from it.
- .codecontextignore at repo root: auto-installed when codecontext
  was first called against /opt/boocode itself; matches the template.
- CLAUDE.md: updated to document the v1.13.11 publishFrame wrapper +
  message_parts table + tool_cost_stats view + DB-integration test
  pattern + host-side smoke endpoint quirk. (Pre-existing in working
  tree before this batch; shipped here for completeness.)

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-05-22 18:58:30 +00:00

7.0 KiB
Raw Blame History

name, description
name description
diagnosing-bugs Disciplined diagnosis loop for hard bugs and performance regressions. Reproduce → minimise → hypothesise → instrument → fix → regression-test. Use when user says "diagnose this" / "debug this", reports a bug, says something is broken/throwing/failing/not working/something wrong, or describes a performance regression.

Diagnose

A discipline for hard bugs. Skip phases only when explicitly justified.

When exploring the codebase, use the project's domain glossary to get a clear mental model of the relevant modules, and check ADRs in the area you're touching.

Phase 1 — Build a feedback loop

This is the skill. Everything else is mechanical. If you have a fast, deterministic, agent-runnable pass/fail signal for the bug, you will find the cause — bisection, hypothesis-testing, and instrumentation all just consume that signal. If you don't have one, no amount of staring at code will save you.

Spend disproportionate effort here. Be aggressive. Be creative. Refuse to give up.

Ways to construct one — try them in roughly this order

  1. Failing test at whatever seam reaches the bug — unit, integration, e2e.
  2. Curl / HTTP script against a running dev server.
  3. CLI invocation with a fixture input, diffing stdout against a known-good snapshot.
  4. Headless browser script (Playwright / Puppeteer) — drives the UI, asserts on DOM/console/network.
  5. Replay a captured trace. Save a real network request / payload / event log to disk; replay it through the code path in isolation.
  6. Throwaway harness. Spin up a minimal subset of the system (one service, mocked deps) that exercises the bug code path with a single function call.
  7. Property / fuzz loop. If the bug is "sometimes wrong output", run 1000 random inputs and look for the failure mode.
  8. Bisection harness. If the bug appeared between two known states (commit, dataset, version), automate "boot at state X, check, repeat" so you can git bisect run it.
  9. Differential loop. Run the same input through old-version vs new-version (or two configs) and diff outputs.
  10. HITL bash script. Last resort. If a human must click, drive them with scripts/hitl-loop.template.sh so the loop is still structured. Captured output feeds back to you.

Build the right feedback loop, and the bug is 90% fixed.

Iterate on the loop itself

Treat the loop as a product. Once you have a loop, ask:

  • Can I make it faster? (Cache setup, skip unrelated init, narrow the test scope.)
  • Can I make the signal sharper? (Assert on the specific symptom, not "didn't crash".)
  • Can I make it more deterministic? (Pin time, seed RNG, isolate filesystem, freeze network.)

A 30-second flaky loop is barely better than no loop. A 2-second deterministic loop is a debugging superpower.

Non-deterministic bugs

The goal is not a clean repro but a higher reproduction rate. Loop the trigger 100×, parallelise, add stress, narrow timing windows, inject sleeps. A 50%-flake bug is debuggable; 1% is not — keep raising the rate until it's debuggable.

When you genuinely cannot build a loop

Stop and say so explicitly. List what you tried. Ask the user for: (a) access to whatever environment reproduces it, (b) a captured artifact (HAR file, log dump, core dump, screen recording with timestamps), or (c) permission to add temporary production instrumentation. Do not proceed to hypothesise without a loop.

Do not proceed to Phase 2 until you have a loop you believe in.

Phase 2 — Reproduce

Run the loop. Watch the bug appear.

Confirm:

  • The loop produces the failure mode the user described — not a different failure that happens to be nearby. Wrong bug = wrong fix.
  • The failure is reproducible across multiple runs (or, for non-deterministic bugs, reproducible at a high enough rate to debug against).
  • You have captured the exact symptom (error message, wrong output, slow timing) so later phases can verify the fix actually addresses it.

Do not proceed until you reproduce the bug.

Phase 3 — Hypothesise

Generate 35 ranked hypotheses before testing any of them. Single-hypothesis generation anchors on the first plausible idea.

Each hypothesis must be falsifiable: state the prediction it makes.

Format: "If is the cause, then will make the bug disappear / will make it worse."

If you cannot state the prediction, the hypothesis is a vibe — discard or sharpen it.

Show the ranked list to the user before testing. They often have domain knowledge that re-ranks instantly ("we just deployed a change to #3"), or know hypotheses they've already ruled out. Cheap checkpoint, big time saver. Don't block on it — proceed with your ranking if the user is AFK.

Phase 4 — Instrument

Each probe must map to a specific prediction from Phase 3. Change one variable at a time.

Tool preference:

  1. Debugger / REPL inspection if the env supports it. One breakpoint beats ten logs.
  2. Targeted logs at the boundaries that distinguish hypotheses.
  3. Never "log everything and grep".

Tag every debug log with a unique prefix, e.g. [DEBUG-a4f2]. Cleanup at the end becomes a single grep. Untagged logs survive; tagged logs die.

Perf branch. For performance regressions, logs are usually wrong. Instead: establish a baseline measurement (timing harness, performance.now(), profiler, query plan), then bisect. Measure first, fix second.

Phase 5 — Fix + regression test

Write the regression test before the fix — but only if there is a correct seam for it.

A correct seam is one where the test exercises the real bug pattern as it occurs at the call site. If the only available seam is too shallow (single-caller test when the bug needs multiple callers, unit test that can't replicate the chain that triggered the bug), a regression test there gives false confidence.

If no correct seam exists, that itself is the finding. Note it. The codebase architecture is preventing the bug from being locked down. Flag this for the next phase.

If a correct seam exists:

  1. Turn the minimised repro into a failing test at that seam.
  2. Watch it fail.
  3. Apply the fix.
  4. Watch it pass.
  5. Re-run the Phase 1 feedback loop against the original (un-minimised) scenario.

Phase 6 — Cleanup + post-mortem

Required before declaring done:

  • Original repro no longer reproduces (re-run the Phase 1 loop)
  • Regression test passes (or absence of seam is documented)
  • All [DEBUG-...] instrumentation removed (grep the prefix)
  • Throwaway prototypes deleted (or moved to a clearly-marked debug location)
  • The hypothesis that turned out correct is stated in the commit / PR message — so the next debugger learns

Then ask: what would have prevented this bug? If the answer involves architectural change (no good test seam, tangled callers, hidden coupling) hand off to the /improve-codebase-architecture skill with the specifics. Make the recommendation after the fix is in, not before — you have more information now than when you started.