- Adds a "promise-failure" command (agent v3.128.0+) to declare an expected hard failure early, letting the build be marked failing while the job continues running useful work.
- Triggers earlier notifications, retry/soft‑fail rules, and enables sibling jobs with cancel_on_build_failing to stop, improving investigation speed without losing logs, artifacts, or teardown.
- Includes AI‑driven guidance for finding long‑running, frequently failing jobs that can benefit, and integrates with Buildkite Test Engine v2.9.0+ via BUILDKITE_TEST_ENGINE_PROMISE_FAILURE.