error($c, "This build cannot be restarted.")
        unless $build->finished && -f $build->drvpath;
    restartBuild($c->model('DB')->schema, $build);

    my $n = restartBuilds($c->model('DB')->schema, $c->model('DB::Builds')->search({ id => $build->id }));
    error($c, "This build cannot be restarted.") if $n != 1;

    $c->res->redirect($c->uri_for($c->controller('JobsetEval')->action_for('view'), $c->req->captures));
}
sub restart_aborted : Chained('eval') PathPart('restart-aborted') Args(0) {
    my ($self, $c) = @_;
    requireProjectOwner($c, $c->stash->{eval}->project);
    my $builds = $c->stash->{eval}->builds->search({ finished => 1, buildstatus => { -in => [3, 4] } });
    my $n = restartBuilds($c->model('DB')->schema, $builds);
    $c->flash->{successMsg} = "$n builds have been restarted.";

sub restartBuild {
    my ($db, $build) = @_;
    txn_do($db, sub {
        my @paths;
        push @paths, $build->drvpath;
        push @paths, $_->drvpath foreach $build->buildsteps;

        my $r = `nix-store --clear-failed-paths @paths`;

        $build->update(
            { finished => 0
            , busy => 0
            , locker => ""
            , iscachedbuild => 0
            });
        $build->buildproducts->delete;
        # Reset the stats for the evals to which this build belongs.
        # !!! Should do this in a trigger.
        foreach my $m ($build->jobsetevalmembers->all) {
            $m->eval->update({nrsucceeded => undef});
        }
    });
}

1;

use Nix::Store;

    cancelBuilds);

    cancelBuilds restartBuilds);

    });
}
sub restartBuilds($$) {
    my ($db, $builds) = @_;
    my $n = 0;
    txn_do($db, sub {
        my @paths;
        $builds = $builds->search({ finished => 1 });
        foreach my $build ($builds->all) {
            next if !isValidPath($build->drvpath);
            push @paths, $build->drvpath;
            push @paths, $_->drvpath foreach $build->buildsteps;
            $build->update(
                { finished => 0
                , busy => 0
                , locker => ""
                , iscachedbuild => 0
                });
            $n++;
            # Reset the stats for the evals to which this build belongs.
            # !!! Should do this in a trigger.
            $build->jobsetevals->update({nrsucceeded => undef});
        }
        # Clear Nix's negative failure cache.
        # FIXME: Add this to the API.
        system("nix-store", "--clear-failed-paths", @paths);

    return $n;

        <li><a href="[% c.uri_for(c.controller('JobsetEval').action_for('restart_aborted'), [eval.id]) %]">Restart all aborted builds</a></li>