outerOperationCompletion = workerRegistry.startWorker()
        outerOperation = workerRegistry.getCurrentWorkerLease()
    }

    static class SimpleWorker implements BuildOperationWorker<DefaultBuildOperationQueueTest.TestBuildOperation> {
        void execute(DefaultBuildOperationQueueTest.TestBuildOperation run, BuildOperationContext context) { run.run(context) }
    }

        given:
        def maxWorkers = 1
        def workerLeaseService = this.workerLeaseService(maxWorkers)
        def processor = createProcessor(workerLeaseService, maxWorkers)
        def processorWorker = new SimpleWorker()

        when:
        async {
            start {
                def cl = workerLeaseService.startWorker()
                instant.worker1
                thread.blockUntil.worker2Ready

    static class Failure extends TestBuildOperation {
        void run(BuildOperationContext buildOperationContext) {
            throw new BuildOperationFailure(this, "always fails")
        }
    }

    static class SimpleWorker implements BuildOperationQueue.QueueWorker<TestBuildOperation> {
        void execute(TestBuildOperation run) {
            run.run(null)
        }

        String getDisplayName() {