Exit 0 means your program exited 0. That’s it. That’s all it means. 🍞 I have been working on a deterministic VM called Rewind VM, where “a run” (i.e. test, command etc.) is a function of its inputs including the thread schedule. The determinism comes from the tool recording every step which lets you replay it exactly. This alone is a pretty good way to find flaky tests: run the test under Rewind, then rewind check runs it under many different thread schedules, with some slight latency added, and failures often crop up. 🐛