#flaky-tests

Catching a Retry Race with One Seed: Deterministic Simulation in Rust using turmoil

I had three flaky retry tests no one could reproduce on a laptop. I rewrote one in Rust on top of turmoil, Tokio's deterministic simulator, and a single 8-byte seed pinned the partition race byte-for-byte. These are my notes on what the seed actually controls, what leaks past it, and when deterministic simulation testing is worth the seam.