[finding] `ctx.log.debug` is inferred, granted and documented, but the sandbox never installs it — a body calling it throws `TypeError: not a function`

[os-help]

Found while fixing #7448 (PR #7660). Out of scope there — that card is the observability of ctx.log.{info,warn,error}; this is a fourth method that does not exist. Filed rather than folded in, per Prime Directive #10. Unassigned — recording only.

The gap

ctx.log.debug is declared on three surfaces and implemented on none.

Surface	Says	Anchor (main @ 245d1dc)
CLI capability extractor	matches debug, grants the log capability	packages/cli/src/utils/extract-hook-body.ts:56 — /ctx\.log\.(?:info|warn|error|debug)\b/
Docs	lists ctx.log.info / warn / error / debug → log	content/docs/automation/hook-bodies.mdx:317
Sandbox ScriptContext	declares info / warn / error only	packages/runtime/src/sandbox/script-runner.ts:243
QuickJS VM install	installs info / warn / error only	packages/runtime/src/sandbox/quickjs-runner.ts:639 — for (const level of ['info', 'warn', 'error'] as const)

So an author writes ctx.log.debug(…), the CLI reads it, infers ['log'] and emits a body whose declared capability is satisfied — and the call then throws inside the VM.

Measured

Hook body ctx.log.debug('hi') with capabilities: ['log'], run through hookBodyRunnerFactory + QuickJSScriptRunner with a logger that has a real debug method:

hook 'h' threw: TypeError: not a function

Not a silent drop — the hook fails. Under onError: 'abort' that aborts the write.

Why this is the crypto.hash shape again

script-runner.ts:249-258 documents the precedent in its own comment: crypto.hash carried a signature, a capability token and CLI build-time inference for a function the sandbox never installed, so the one call it typed threw inside the VM. It was removed rather than implemented (#4391, ADR-0049 enforce-or-remove). ctx.log.debug is the same shape one member over — and unlike hashing it has no security-surface argument against implementing it.

Decision needed (enforce-or-remove)

• Enforce — add debug to the VM install loop and to ScriptContext['log']. Cheap; Logger.debug(message, meta) already exists on the contract (packages/spec/src/contracts/logger.ts:15), and after [finding] Hook body ctx.log output is unobservable — body-runner wires log: engineCtx?.logger with no fallback, so the declared ['log'] capability can silently produce nothing #7448 the capability is served from a real Logger that has it.
• Remove — drop debug from the extractor regex and the docs table, so the three surfaces agree on three methods.

Enforcing looks right here (a body emitting debug-level diagnostics is exactly what --log-level debug is for), but it is a capability-surface call, not a bug fix, so it should be decided rather than assumed.

Dedup

Searched open issues for ctx.log, log.debug, capability log, extract-hook-body: no existing card. #7448 is the adjacent one and covers only the three installed methods.

[claude]

Route repair (finding triage route A): domain:cli appended — routing only; the finding grade is unchanged and no ownership is taken.

Landing site read, not guessed: whichever arm of the enforce-or-remove fork wins, the diff lands in domain:cli packages — enforce touches packages/runtime/src/sandbox/quickjs-runner.ts:639 (the ['info', 'warn', 'error'] install loop, verified on origin/main @ 6a9dec6) plus script-runner.ts's ScriptContext; remove touches packages/cli/src/utils/extract-hook-body.ts:56 (the extractor regex, verified — debug still in the alternation) plus the docs table. Both packages/runtime and packages/cli sit in the domain:cli row of the lane table.

Dedup: #7448 (the ctx.log observability card, pm:dispatched) explicitly scopes this out and PR #7660 does not touch the debug member; no other open card names ctx.log.debug.

本评论来自分诊座位 Routine（#5474 试点），不构成认领。

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[os-zhuang]

Findings triage round, 2026-08-11 (PM session, maintainer-directed: 「跑一轮集中定级」).

Graded: promote. ctx.log.debug is declared on three surfaces (extractor grants it, docs teach it) and installed on none — an author following the documentation gets TypeError: not a function. Declared = enforced, live author impact, S-M fix (install debug in the sandbox, or retire it from all three declaring surfaces in one pass — implementer measures which direction ADR posture prefers).

finding → pm:queue (domain:cli).

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Generated by Claude Code

[hotlong]

Claim: PM loop round 2 — domain:cli seat.

• Session: session_01B3Kurx8qufrDzNjk4rag7V (account hotlong)
• Branch: claude/issue-7661-ctx-log-debug
• Worktree: objectstack-issue-7661
• Domain: domain:cli
• File surface: packages/runtime/src/sandbox/quickjs-runner.ts (the install loop ~:639), packages/runtime/src/sandbox/script-runner.ts (ScriptContext['log'] ~:243), plus their tests. ⛔ Not packages/cli/src/utils/extract-hook-body.ts and not the docs table — those are already correct under the ruling below. Stop on breach.
• Container & model: M, mode:subagent (cloud dispatch unavailable — sanctioned fallback), model: opus.
• Serial constraints cleared: runtime/src/sandbox/** is untouched by every in-flight cli claim (finding: /meta/_drafts serves DRAFT object schemas unmasked — the one ADR-0106 outlet left uncovered #6599 = rest-server.ts + runtime/domains/meta.ts; [finding] packages.ts:337 promises a wire-field rename that the objectui follow-up measured out — the comment is now a false pointer #7578 = runtime/domains/packages.ts; mcp-stdio-fail-closed c3: the stdio MCP transport starts but is permanently deaf (oclif arg parser pauses process.stdin) #7645 = packages/mcp). Disjoint.

Ruling: ENFORCE, on a named and falsifiable premise

Taking this as a restore-invariant call (declared = enforced) rather than escalating: ADR-0049 governs, and the two arms are not evenly matched here. debug is already granted by the extractor and already taught by the docs, so the three surfaces disagree in the direction of promising more than we deliver — the class the invariant exists to close.

Direction: enforce — install debug in the VM loop and declare it on ScriptContext['log'], so all four surfaces agree on four methods.

The premise this ruling hangs on (verify BEFORE writing code): Logger.debug(message, meta) exists on the contract (packages/spec/src/contracts/logger.ts:15) and the logger the log capability is actually served from after #7448 really carries a callable debug. If either half is false — the contract lacks it, or the served logger would throw/no-op — ⛔ do not implement, and ⛔ do not silently switch to the remove arm. Report the fork with the measurement; the direction becomes a maintainer call at that point.

Why not the remove arm by default: the cited precedent (crypto.hash, #4391) was removed because implementing it meant opening a security surface. Emitting a debug-level diagnostic from a hook body has no such argument, and --log-level debug is exactly what such a body is for. That asymmetry is the whole reason this is rulable rather than escalatable — if the dev's measurement contradicts it, the ruling loses its basis and the fork comes back.

Pin the consequence: the reproduction in this card — a hook body calling ctx.log.debug('hi') with capabilities: ['log'], run through hookBodyRunnerFactory + QuickJSScriptRunner — must go from TypeError: not a function to a delivered debug record. Assert the record reaches the logger, not merely that no throw occurred: a debug installed as a no-op would pass a throw-only test and still not be a real fourth method.

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Generated by Claude Code

[hotlong]

Dispatch-mode correction to the claim above: mode:subagent → mode:cloud.

Cloud dispatch was unavailable when I wrote the claim and became available minutes later, so this card is dispatched the way #7341 requires (M and above default to a dedicated cloud container) rather than the shared-container fallback.

• Cloud session: session_01CUymLqPDq3d7PgiwpZsbA2
• Title: cli #7661 ctx.log.debug declared but never installed
• Model: claude-opus-5, outcome_branch: claude/issue-7661-ctx-log-debug

Everything else in the claim stands unchanged — the ENFORCE ruling, the two-part premise it hangs on (contract Logger.debug exists AND the served logger really carries a callable debug), the ⛔ do-not-silently-switch-to-remove clause, and the pin that the debug record must actually reach the logger rather than merely not throw.

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