[miguel-heygen]

What changes

A seek waits for everything it started (video frames, frame sources, scene windows, motion blur, effects, image decodes) before a frame is captured. If one of those holds never settled, check and snapshot sat until Puppeteer's protocol timeout (180 s) fired, with a message that said nothing about why.

Now the caller can bound the wait, and the error names what is still pending:

seek did not settle within 170000 ms: still waiting on frame-source

• __hfWaitForSeekCompletion({ timeoutMs }) ends at the caller's limit. Without timeoutMs it waits as before, so export renders keep the limits they already had: protocolTimeout, scaled by canvas size and settable by the user.
• check (the overlap grid) and snapshot / settleCompositionSeek pass SEEK_SETTLES_BEFORE_PROTOCOL_TIMEOUT_MS, which is 170 s, 10 s under the protocol timeout their browser runs with. A seek that used to finish still finishes; one that used to die at 180 s with an opaque timeout now fails at 170 s, named. The grid runs all its seeks in one page call, so it spends one 170 s budget across all of them.
• Every hold registers with its kind (registerSeekCompletion(promise, hold)), so the error can say which one is stuck.
• Holds registered while the barrier waits share the same deadline; a stream of new holds can't extend it.

What it does not fix

• It does not make a slow seek faster.
• It does not fix the many-clips snapshot hang. That is a renderer crash, handled separately.

Tests

seek-dispatch.test.ts:

• A hold that never settles ends at the caller's deadline and is named.
• Holds registered while waiting end at the same deadline, in under 1 s.
• With no timeoutMs, a seek waits as long as its holds take (fake timers, 30 min).
• Holds that settle in time resolve as before.

fails without the fix: packages/core/src/runtime/adapters/seek-dispatch.test.ts "a seek with a hold that never settles ends at its deadline, naming what it still waits on" and "holds registered while the barrier waits still end at the same deadline": on main the wait has no deadline, so both run into vitest's 5 s timeout; on this branch they pass, 3 runs in a row. The CLI capture tests now expect the limit to be passed.

Results on Linux:

• Core seek tests: 3 runs in a row, 14/14 each time.
• Full CLI unit project: 418 files, 5810 tests.
• Fallow audit: clean.

[heygengenesis]

Verdict: REQUEST CHANGES · 1 blocker · 0 important · 0 nits · head c74bb142

The 30 s default also applies to export renders, not just check/snapshot. That turns renders that are slow but valid into failures. Details inline.

Scope and checks

• Read all 7 files. Also checked every caller of __hfWaitForSeekCompletion: engine frameCapture/drawElementService/riskFrames/videoFrameInjector, cli captureCompositionFrame/checkBrowser/motionShot, and studio useShadowPreviewReload. None of them pass timeoutMs.
• The producer's virtual-time shim freezes Date.now while the barrier waits, so deadline - Date.now() still works out to 30 s of real time. That part is fine.
• Ran locally on the head: seek-dispatch, init.seekOrder and frameSources tests (35 pass); core tsc is clean. CI was still running when I posted.

[heygengenesis]

blocker: every engine/producer render goes through this default. waitForPendingSeekCompletion (engine frameCapture.ts:3190) calls __hfWaitForSeekCompletion() with no options. The 180 s in the PR body is the CLI's Puppeteer default (captureTimeout.ts). Renders run under protocolTimeout, which is 300 s by default, scales with canvas area up to 30 min (scaleProtocolTimeoutForComposition exists because slow-but-valid seek/paint calls on large canvases were being killed), and can be raised by the user.

So with this change, a render that used to finish now fails after 30 s, with no way to raise the limit. Example: a frame source whose ready loads a heavy model or scene for 45 s on a cold worker. docs/guides/frame-sources.md says "ready holds initialization and export capture" and documents no limit. The same goes for a slow software-GL vfx/motion-blur paint at 4K.

Fix: have the engine pass timeoutMs derived from its effective protocol timeout, minus a margin so the named error still wins the race. Keep 30 s, or the CLI's budget, for check/snapshot. If 30 s is meant to be the new contract for renders too, document it in the frame-sources guide and make it configurable.

[miguel-heygen]

Agreed, fixed in ce1d96b. The core wait no longer has a default limit: without timeoutMs it waits as before, so renders keep their scaled protocolTimeout. Only the CLI's check grid and settleCompositionSeek (snapshot) pass a limit, 170 s, 10 s under the 180 s protocol timeout their browser runs with. Anything that finished before still finishes; a seek that hit the opaque 180 s timeout now fails at 170 s and names the stuck hold.

[heygengenesis]

✅ Fixed in ce1d96b. The core wait has no default limit anymore, so renders keep their scaled protocolTimeout. Only check and snapshot pass 170 s.

[github-actions]

Edit accuracy: accurate 271 (base branch 271), smooth 143 of those

The gate passes.
Smoothness is reported in the artifact, not gated. A case fails only if it fails 2 of 3 runs.

Quarantined, measured but not gated (0)

Unstable (2)

• seqplainkeys-none-pct-r0-root-z100: tracking 0.06, pressJump 0, drop 0, reload 0, render 0.03, renderKey -, undo false, teleport true / tracking 0.06, pressJump 0, drop 0, reload 0, render 0.03, renderKey -, undo true, teleport true / tracking 0.06, pressJump 0, drop 0, reload 0, render 0.03, renderKey -, undo true, teleport true
• seqrotatenudge-none-pct-r0-nested-z100: tracking 0.02, pressJump 0, drop 0, reload 3.03, render 0.06, renderKey -, undo false, teleport true / tracking 0.02, pressJump 0, drop 0, reload 0, render 0.06, renderKey -, undo true, teleport true / tracking 0.02, pressJump 0, drop 0, reload 0, render 0.06, renderKey -, undo true, teleport true

[heygengenesis]

Verdict: APPROVE — 1 resolved, 0 open, 0 new · c74bb14 → ce1d96b. CI is green; the first CI run lost edit-accuracy shard 4 to a stalled Chrome download, and the second run on this head passed.