private static void BuildIfOutOfDate(bool runBuildsAsync, ReferencedFileSave rfs)
        {
            if (rfs.GetIsBuiltFileOutOfDate())
            {
                string error = rfs.PerformExternalBuild(runAsync: runBuildsAsync);

                if (!string.IsNullOrEmpty(error))
                {
                    ErrorReporter.ReportError(ProjectManager.MakeAbsolute(rfs.Name, true), error, false);
                }
            }
        }