Step one towards stable error messages with details:

pkg/pkg.status

Index: pkg/pkg.status
diff --git a/pkg/pkg.status b/pkg/pkg.status
index e4d5091de1c5924ef63d30d4c7898da6e4d75983..2e543d67e75462909d3debb010f28a984d2eb46d 100644
--- a/pkg/pkg.status
+++ b/pkg/pkg.status
@@ -108,6 +108,9 @@ analysis_server/test/services/index/store/codec_test: Pass, Slow
 # subprocess.
 analysis_server/test/integration: Skip
 
+polymer/test/build/unique_message_test: Skip # Intended only as a vm test.
+code_transformers/test/unique_message_test: Skip # Intended only as a vm test.
+
 [ $compiler == dart2js && $runtime == ff && $system == windows ]
 http/test/html/client_test: Fail # Issue 19750
 scheduled_test/test/scheduled_stream/scheduled_stream_test: Fail # Issue 19750
@@ -313,7 +316,10 @@ analysis_server/test/*: Skip # Uses dart:io.
 analysis_server/tool/spec/check_all_test: Skip # Uses dart:io.
 analyzer/test/*: Skip # Uses dart:io.
 barback/test/*: Fail, OK # Uses dart:io.
-code_transformers/test/*: Skip # Uses dart:io.
+code_transformers/test/assets_test: Skip # Uses dart:io
+code_transformers/test/entry_point_test: Skip # Uses dart:io
+code_transformers/test/resolver_test: Skip # Uses dart:io
+code_transformers/test/unique_message_test: Skip # Uses dart:io
 http/test/io/*: Fail, OK # Uses dart:io.
 http_parser/test/web_socket_test: Fail, OK # Uses dart:io
 http_multi_server/test/http_multi_server_test: Skip # Uses dart:io