菜单
Use when analyzing a Chrome/Electron DevTools Performance trace export (.json) — slow renders, long tasks, jank, CPU sample attribution, "where is the time actually going".
用 Codex 或 Claude 帮你安装 复制这段 Prompt，粘贴到 Codex、Claude 或其他助手里，让它检查 Skill 页面并帮你完成安装。
基于 SOC 职业分类
| name | electron-profile |
| description | Use when analyzing a Chrome/Electron DevTools Performance trace export (.json) — slow renders, long tasks, jank, CPU sample attribution, "where is the time actually going". |
Parse DevTools Performance panel exports with Python scripts in scripts/ — no DevTools UI needed. A trace is one big JSON of traceEvents; a 400MB export loads in ~30s. The embedded sampling profile lives in Profile/ProfileChunk events.
python3 scripts/trace-overview.py <trace.json> [--long-ms 50] [--top 30]
--window (seconds, relative to first sample) to zoom into a long task found in step 1:
python3 scripts/trace-samples.py <trace.json> [--window FROM_S TO_S] [--top 30]
Both auto-pick the busiest CrRendererMain; override with --pid/--tid. Both need scripts/tracelib.py alongside.
Dev-build traces are ~85-90% React dev instrumentation, NOT app code. Absolute numbers are meaningless; prod is ~10x faster. For real numbers profile the prod bundle (see prod-bundles skill), or at minimum disable the React DevTools extension while recording.
| Signal | Meaning |
|---|---|
Huge run (:-1) self time, createTask, measure | React 19 dev component-performance tracks: console.createTask().run() inside runWithFiberInDEV/logComponentRender. Not app code. |
v8::Debugger::AsyncTaskRun dominating X-event totals | Debugger async-stack tracking (DevTools open). Dev artifact. |
| Effects firing twice back-to-back | StrictMode double-invoke. Dev only. |
| 90%+ samples with no app frame on stack | Expected in dev — instrumentation + framework internals. Judge the app-frame report's relative ranking, not totals. |
performSyncWorkOnRoot ≫ scheduler time in inclusive report | Most renders are sync (flushSync / discrete events), not concurrent. Structural signal — valid even in dev. |
pptr:internal frames | CDP automation harness driving the app, not app code (excluded from app-frame report). |
| Layout / Paint / GC / EventDispatch totals in overview | Real browser work — valid signal even in dev. Compare against script time. |
Judge structure, not magnitude in dev traces: sync-vs-concurrent split, Layout/Paint/GC share, which app components rank highest, burst patterns around long tasks.
node_modules — with Vite dev this automatically excludes React (node_modules/.vite/deps/...).--window is relative to the first sample, not trace start; long-task t= offsets from the overview are relative to trace start. They usually differ by <1s but eyeball the sample span line.Use when updating npm/yarn dependencies in shared/package.json, protocol/, or rnmodules/react-native-kb/. Use for routine dep bumps, security updates, or keeping packages current.
Use when analyzing a React DevTools Profiler export (.json with "dataForRoots"/"commitData") — re-render storms, commit fan-out, "why did this component render", send/interaction render cost. NOT for Chrome Performance traces (those have "traceEvents" — use electron-profile).
Use when analyzing a V8/Chrome/Electron .heapsnapshot file — memory leak hunting, detached DOM nodes, "why is this object retained", growing heap, retainer paths.
Use when asked to look at or address feedback on a PR. Fetches Copilot-only inline comments, skips hidden ones, then evaluates and fixes the valid ones.
Use when writing, fixing, or adding e2e flow tests for the Keybase app — desktop (Playwright) or iOS (Maestro). Covers testID conventions, navigation patterns, common pitfalls, and the two-harness structure.
Use when upgrading the Keybase client version number - lists all files that must be updated together