anchor.diff:    var sinceMap = <String, SinceInfo>{};
     for (var lint in registeredLints.map((l) => l.name)) {
       var linterVersion = linterVersionCache[lint];
  +    if (linterVersion == null) {
  +      linterVersion = await findSinceLinter(lint);
  +      if (linterVersion != null) {
  +        print('fetched...');
  +        print('$lint : $linterVersion');
  +        print('(consider caching in tool/since/linter.yaml)');
  +      }
  +    }
       sinceMap[lint] = new SinceInfo(
           sinceLinter: linterVersion ?? await findSinceLinter(lint),
           sinceDartSdk: await _sinceSdkForLinter(linterVersion));
  
positive.code: import 'crawl.dart';
  
  main() async {
  // TODO(pq): make dynamic or update tests to ensure this stays in sync.
  // Uncomment to (re)generate since/linter.yaml contents.
  //  for (var lint in registeredLints) {
  //    var since = await findSinceLinter(lint.name);
  
negative.code:         _dartSdkMap[sdk] = linterVersion;
          print('fetched...');
          print('$sdk : $linterVersion');
          print('(consider caching in tool/since/dart_sdk.yaml)');
        }
      }
    }
  