fix(test): deflake ensure_warm parallel-promote timing assertion - #562
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ensure_warm_for_dispatch_promotes_in_parallel asserted both loader.peak() >= 2 (deterministic: concurrent loads observed) and elapsed < 1.5x delay (a wall-clock proxy). The wall-clock bound flaked on cold/contended CI runners (notably Windows, where the nightly-2026-07-14 cache miss plus blocking-pool ramp-up pushed even a correct parallel run past 150ms), which ejected release PR #560 from the merge queue. The peak-in-flight counter already proves the parallelism contract with no timing race: a serial re-promote loop never exceeds peak 1. Drop the redundant wall-clock assertion and rely on the deterministic signal.
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Problem
index::tests::ensure_warm::ensure_warm_for_dispatch_promotes_in_parallelflaked on the Windows merge-queue runner and ejected release PR #560 from the queue (panic atensure_warm.rs:328).The test made two parallelism assertions:
loader.peak() >= 2— deterministic: theSlowBodyLoaderrecords peak concurrent in-flightload()calls; a parallel fan-out sees ≥ 2, a serial loop sees 1.elapsed < 1.5 × delay(150 ms) — a wall-clock proxy.On a cold/contended runner (the nightly-2026-07-14 cache miss + tokio blocking-pool ramp-up), assertion 2 blew its bound even when the fan-out ran correctly in parallel — a timing race, not a real regression.
Fix
Drop the redundant wall-clock assertion; keep the deterministic peak-in-flight counter, which already pins the parallelism contract (a serial re-promote loop can never exceed peak 1). No production code changed — test-only.
Verified locally:
cargo nextest run -p uffs-daemon ensure_warm_for_dispatch_promotes_in_parallel→ passes (0.13s).