Optional ReadonlyattemptFurthest progress across this Step method call's attempts. SDK-provided contexts always include a value. Omitted values remain accepted for source compatibility. Treat UNSPECIFIED or an omitted value like NOT_COMPLETED. See StepAttemptProgress for a recovery example.
ReadonlydetailFailure message supplied by the Worker or backend.
ReadonlyerrorOriginal Worker error type or backend failure type.
Describes the final failure that selected a recovery path.