$query .= " and (select count(*) from buildinputs where build = $id and name = '$name' and value = '$value') = 1";

        $query .= " and exists (select 1 from buildinputs where build = $id and name = '$name' and value = '$value')";

}
sub parseJobName {
    # Parse a job specification of the form `<project>:<jobset>:<job>
    # [attrs]'.  The project, jobset and attrs may be omitted.  The
    # attrs have the form `name = "value"'.
    my ($s) = @_;
    our $key;
    our %attrs = ();
    # hm, maybe I should stop programming Perl before it's too late...
    $s =~ / ^ (?: (?: ([\w\-]+) : )? ([\w\-]+) : )? ([\w\-]+) \s*
            (\[ \s* (
              ([\w]+) (?{ $key = $^N; }) \s* = \s* \"
              ([\w\-]+) (?{ $attrs{$key} = $^N; }) \"
            \s* )* \])? $
          /x
        or die "invalid job specifier `$s'";
    return ($1, $2, $3, \%attrs);
}
sub attrsToSQL {
    my ($attrs, $id) = @_;
    my $query = "1 = 1";
    foreach my $name (keys %{$attrs}) {
        my $value = $attrs->{$name};
        $name =~ /^[\w\-]+$/ or die;
        $value =~ /^[\w\-]+$/ or die;
        # !!! Yes, this is horribly injection-prone... (though
        # name/value are filtered above).  Should use SQL::Abstract,
        # but it can't deal with subqueries.  At least we should use
        # placeholders.
        $query .= " and exists (select 1 from buildinputs where build = $id and name = '$name' and value = '$value')";
    }
    return $query;

        my $jobName = $alt->value or die;

        my ($projectName, $jobsetName, $jobName, $attrs) = parseJobName($alt->value);
        $projectName ||= $project->name;
        $jobsetName ||= $jobset->name;

            {finished => 1, project => $project->name, jobset => $jobset->name, job => $jobName, buildStatus => 0},
            {join => 'resultInfo', order_by => "me.id DESC", rows => 1});

            { finished => 1, project => $projectName, jobset => $jobsetName
            , job => $jobName, buildStatus => 0 },
            { join => 'resultInfo', order_by => "me.id DESC", rows => 1
            , where => \ attrsToSQL($attrs, "me.id") });

            print STDERR "no previous build available for `$jobName'";

            print STDERR "input `", $input->name, "': no previous build available\n";

        #print STDERR "input `", $input->name, "': using build ", $prevBuild->id, "\n";

sub checkJobSet {

sub checkJobset {

    $db->txn_do(sub {
        $jobset->update({lastcheckedtime => time});
    });

        $jobset->update({lastcheckedtime => time});
        

sub checkJobs {

sub checkJobsetWrapped {
    my ($project, $jobset) = @_;
    
    print "considering jobset ", $jobset->name, " in ", $project->name, "\n";
    
    eval {
        checkJobset($project, $jobset);
    };
    
    if ($@) {
        my $msg = $@;
        print "error evaluating jobset ", $jobset->name, ": $msg";
        $db->txn_do(sub {
            $jobset->update({lastcheckedtime => time});
            setJobsetError($jobset, $msg);
        });
    }
}

sub checkJobs {

        foreach my $jobset ($project->jobsets->all) {
            print "considering jobset ", $jobset->name, " in ", $project->name, "\n";
            eval {
                checkJobSet($project, $jobset);
            };
            if ($@) {
                print "error evaluating jobset ", $jobset->name, ": $@";
                setJobsetError($jobset, $@);
            }
        }

        checkJobsetWrapped($project, $_) foreach $project->jobsets->all;

    checkJobSet($jobset->project, $jobset);

    checkJobsetWrapped($jobset->project, $jobset);