macro_rules! buggify_knob {
($default:expr, $range:expr) => { ... };
}Expand description
Buggify a config knob value within bounds.
buggify_knob!(default, lo..hi) evaluates to default on most seeds, but when
buggify is enabled and this call site is activated + fires (same model as
buggify!) it evaluates to a random value in lo..hi. Deterministic per
(location, seed), so replay is exact. Mirrors FoundationDB’s
if (randomize && BUGGIFY) KNOB = random(lo, hi).