/* Sort the runnable steps by priority. Priority is establised
           as follows (in order of precedence):
           - The global priority of the builds that depend on the
             step. This allows admins to bump a build to the front of
             the queue.
           - The lowest used scheduling share of the jobsets depending
             on the step.

        /* Sort the runnable steps by priority. FIXME: O(n lg n);
           obviously, it would be better to keep a runnable queue sorted
           by priority. */

           - The local priority of the build, as set via the build's
             meta.schedulingPriority field. Note that this is not
             quite correct: the local priority should only be used to
             establish priority between builds in the same jobset, but
             here it's used between steps in different jobsets if they
             happen to have the same lowest used scheduling share. But
             that's not every likely.
           - The lowest ID of the builds depending on the step;
             i.e. older builds take priority over new ones.
           FIXME: O(n lg n); obviously, it would be better to keep a
           runnable queue sorted by priority. */

                    a_->highestLocalPriority != b_->highestLocalPriority ? a_->highestLocalPriority > b_->highestLocalPriority :

            ("select id, project, jobset, job, drvPath, maxsilent, timeout, timestamp, globalPriority from Builds "

            ("select id, project, jobset, job, drvPath, maxsilent, timeout, timestamp, globalPriority, priority from Builds "

            build->localPriority = row["priority"].as<int>();

        step_->highestLocalPriority = std::max(step_->highestLocalPriority, localPriority);

    int globalPriority;

    int localPriority, globalPriority;

        /* The highest local priority of any build depending on this
           step. */
        int highestLocalPriority{0};