PonyTest now has a --shuffle option that randomizes the order tests are dispatched. This catches a class of bug that's invisible under fixed ordering: test B passes, but only because test A ran first and left behind some state. You won't find out until someone removes test A and something breaks in a way that's hard to trace.
Use --shuffle for a random seed or --shuffle=SEED with a specific U64 seed for reproducibility. When shuffle is active, the seed is printed before any test output:
Test seed: 8675309
Grab that seed from your CI log and pass it back to reproduce the exact ordering:
./my-tests --shuffle=8675309
Shuffle applies to all scheduling modes. For CI environments that run tests sequentially to avoid resource contention, --sequential --shuffle is the recommended combination: stable runs without flakiness, and each run uses a different seed so test coupling surfaces over time instead of hiding forever.
--list --shuffle=SEED shows the test names in the order that seed would produce, so you can preview orderings without running anything.