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ios-log-diagnose

Testing & Quality
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Drive the UniClipboard iOS app in a simulator and read its OSLog yourself to diagnose a mobile-sync bug, instead of asking the user to paste logs. Use when debugging why the iOS sync engine or M5 reducer did something, reproducing an iOS sync / clipboard bug on the simulator, or whenever you'd otherwise ask the user "what do the logs say". All output is Swift OSLog under subsystem `app.uniclipboard` — the Rust core (uc-mobile) emits no logs of its own; the Swift shell logs the reducer's decisions.

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Source SKILL.md: https://github.com/UniClipboard/UniClipboard/blob/HEAD/.claude/skills/ios-log-diagnose/SKILL.md

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ios-log-diagnose

Read the UniClipboard iOS app's logs yourself. The mobile-sync decision core lives in Rust (uc-mobile reducer), but it has no logger — the Swift SyncEngine shell logs every reducer decision and outcome to OSLog. So one OSLog stream shows both the native Swift logic and the Rust core's behavior.

iOS app repo: /Users/mark/MyProjects/iOSApp/UniClipboard. The reducer-path log harness lives in UniClipboard/Sync/SyncEngine.swift (commit e94ffd1).

The helper is .claude/skills/ios-log-diagnose/ios-logs.sh — the only thing to invoke. Don't hand-roll simctl/log pipelines unless it can't express what you need (macOS has no timeout; the script wraps log stream in a perl alarm — reproducing that by hand is the usual mistake).

Two channels — pick by what you're after

Log level decides where a line goes. This split is the whole mental model:

  • debug → live only, never persisted. The per-tick decision trace: sync preamble: proceed/stop(...), sync route: converged/server-new/push(...), push silent-skip. Seen ONLY by streaming while it happens. Use to watch what the reducer decides each tick.
  • notice / error → persisted, queryable after the fact. The event trail: sync apply/stage/push/consent-push, sync history: round done, the five handle_* transitions, and tick: SyncError .... Use to reconstruct what already happened.

So: streaming a reproduction answers "what is it deciding right now"; show answers "what happened in the last N minutes".

Steps

  1. Drive — boot a sim, install the newest build, inject the Rust-core flag ON + an active server, launch:

    .claude/skills/ios-log-diagnose/ios-logs.sh drive [SERVER_URL]

    The engine only ticks with an active server, so drive always injects one. A dead URL (the default) still exercises preamble → proceed → getClipboard fails → tick: SyncError → backoff — enough to see decisions + the error path. For the happy path (route/apply/push/converge), pass a SERVER_URL that actually returns data (a running uniclipd mobile-sync server). Completion: the command prints injected: flag=ON server=... and a launch PID.

  2. Read — choose the channel:

    .claude/skills/ios-log-diagnose/ios-logs.sh stream [SECONDS] [CATEGORY]   # live debug, default 15s
.claude/skills/ios-log-diagnose/ios-logs.sh show   [DURATION] [CATEGORY]  # persisted notice/error, default 5m

    CATEGORY (optional): sync (SyncEngine — reducer + tick; the usual one), network (HTTP client / connect-uri), store (persistence), app, intents. Omit for every category under app.uniclipboard. Completion: you have the sync (or target) lines for the run you triggered, and can name what the reducer decided / what failed.

Gotchas

  • No content, ever. Logs carry states / bools / counts / decision enums plus an 8-char hashTag prefix — a one-way SHA fingerprint that correlates one clipboard item across pull → stage → apply → push → converge, never the content.
  • Flag injection is forward-safe. drive writes mobileCore.syncClientUsesRustCore = YES. Once the native A/B paths are deleted and Rust is the only path, that key just goes unread — the script keeps working unchanged.
  • App Group, not the app sandbox. Flag + server live in defaults suite group.app.uniclipboard.UniClipboard; injecting them needs a terminate + launch so loadServers re-reads. drive handles this.
  • More injection hooks exist. grep ProcessInfo.processInfo.environment in the iOS repo for UC_* (e.g. UC_DEVICE_TEXT to seed a device copy, UC_TEST_QR_PAYLOAD to add a server via connect-uri) — passed through SIMCTL_CHILD_<NAME>=value on launch.
  • Build first if drive says "no built UniClipboard.app": xcodebuild -scheme UniClipboard -sdk iphonesimulator -destination 'generic/platform=iOS Simulator' build CODE_SIGNING_ALLOWED=NO.