code: private List<Snippet> compileFailResult(BaseTask xt, String userSource, Kind probableKind) {
          return compileFailResult(xt.getDiagnostics(), userSource, probableKind);
      }
docs: The snippet has failed, return with the rejected snippet
  
  @param xt the task from which to extract the failure diagnostics
  @param userSource the incoming bad user source
  @return a rejected snippet