std::vector<BuildID> buildIDs;

                buildIDs.push_back(b->id);

        /* Send notification about this build. */
        {
            auto notificationSenderQueue_(notificationSenderQueue.lock());
            notificationSenderQueue_->push(NotificationItem(build->id, std::vector<BuildID>()));

        /* Send notification about the builds that have this step as
           the top-level. */
        for (auto id : buildIDs) {
            {
                auto notificationSenderQueue_(notificationSenderQueue.lock());
                notificationSenderQueue_->push(NotificationItem(id, std::vector<BuildID>()));
            }
            notificationSenderWakeup.notify_one();

        notificationSenderWakeup.notify_one();

                    dependentIDs.push_back(build2->id);

                dependentIDs.push_back(b->id);