Adding a not explicit source makes it explicit.

pkg/analysis_server/lib/src/services/refactoring/rename_class_member.dart

 // Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library services.src.refactoring.rename_class_member;
 
 import 'dart:async';
 
 import 'package:analysis_server/src/protocol_server.dart'
     hide Element, ElementKind;
@@ skipping 84 matching lines @@
     List<SearchMatch> nameMatches =
         await searchEngine.searchMemberReferences(oldName);
     List<SourceReference> nameRefs = getSourceReferences(nameMatches);
     for (SourceReference reference in nameRefs) {
       // ignore resolved reference, we have already updated it
       if (reference.isResolved) {
         continue;
       }
       // ignore references from SDK and pub cache
       if (isElementInSdkOrPubCache(reference.element)) {
-        print('ignore: $reference');
         continue;
       }
       // check the element being renamed is accessible
       {
         LibraryElement whereLibrary = reference.element.library;
         if (!element.isAccessibleIn(whereLibrary)) {
           continue;
         }
       }
       // add edit
@@ skipping 171 matching lines @@
       Element refElement = reference.element;
       LibraryElement refLibrary = refElement.library;
       if (refLibrary != library) {
         String message = format("Renamed {0} will be invisible in '{1}'.",
             getElementKindName(element), getElementQualifiedName(refLibrary));
         result.addError(message, newLocation_fromMatch(reference));
       }
     }
   }
 }