then:
        1 * clientsManager.reserveIdleClient(options) >> client
        1 * buildOperationRunner.call(_)
    }

    def "build worker operation is finished even if worker fails"() {
        when:
        factory.getWorker(requirement).execute(spec)

        then:
        1 * clientsManager.reserveIdleClient(options) >> client

        return clientsManager.reserveNewClient(forkOptions)
    }

    private WorkerDaemonClient reserveIdleClient(DaemonForkOptions forkOptions) {
        return clientsManager.reserveIdleClient(forkOptions)
    }

    private JavaForkOptions javaForkOptions(String minHeap, String maxHeap, List<String> jvmArgs) {
        def options = TestFiles.execFactory().newJavaForkOptions()

    def "does not reserve idle client when no clients"() {
        expect:
        manager.reserveIdleClient(options) == null
    }

    def "does not reserve idle client when no matching client found"() {
        def noMatch = Stub(WorkerDaemonClient) {
            isCompatibleWith(_) >> false
        }

        expect:
        manager.reserveIdleClient(options, [noMatch]) == null
    }

    def "reserves idle client when match found"() {

    }

    // TODO - should supply and check for the same parameters as passed to reserveNewClient()
    public WorkerDaemonClient reserveIdleClient(DaemonForkOptions forkOptions) {
        return reserveIdleClient(forkOptions, idleClients);
    }

    WorkerDaemonClient reserveIdleClient(DaemonForkOptions forkOptions, List<WorkerDaemonClient> clients) {
        synchronized (lock) {

            private WorkerDaemonClient reserveClient() {
                DaemonForkOptions forkOptions = ((ForkedWorkerRequirement) workerRequirement).getForkOptions();
                WorkerDaemonClient client = clientsManager.reserveIdleClient(forkOptions);
                if (client == null) {
                    client = clientsManager.reserveNewClient(forkOptions);
                }
                return client;
            }
        };
    }