printMsg(lvlDebug, format("sending closure of ‘%1%’ to ‘%2%’") % step->drvPath % machine->sshName);
        MaintainCount mc(nrStepsCopyingTo);

        auto mc1 = std::make_shared<MaintainCount>(nrStepsWaiting);

        mc1.reset();
        MaintainCount mc2(nrStepsCopyingTo);
        printMsg(lvlDebug, format("sending closure of ‘%1%’ to ‘%2%’") % step->drvPath % machine->sshName);

        root.attr("nrStepsWaiting", nrStepsWaiting);

    counter nrStepsWaiting{0};

    gauge("hydra.queue.steps.waiting", $json->{nrStepsWaiting});