internal void ClearBuiltTargetsForProject (Project project)
{
string project_key = project.GetKeyForTarget (String.Empty, false);
var to_remove_keys = BuiltTargetsOutputByName.Keys.Where (key => key.StartsWith (project_key)).ToList ();
foreach (string to_remove_key in to_remove_keys)
BuiltTargetsOutputByName.Remove (to_remove_key);
}