Use the cached pubspec if possible for describing hosted packages.

utils/tests/pub/command_line_config.dart

Index: utils/tests/pub/command_line_config.dart
diff --git a/utils/tests/pub/command_line_config.dart b/utils/tests/pub/command_line_config.dart
index 9a60951be7c30c88b9e7aeef2a8799c89f8f7d9a..47c68a9bef5423aba7567b289bec4b6b9346b47d 100644
--- a/utils/tests/pub/command_line_config.dart
+++ b/utils/tests/pub/command_line_config.dart
@@ -154,7 +154,7 @@ class _StackFrame {
     if (match == null) {
       match = coreRegExp.firstMatch(text);
       if (match == null) {
-        throw FormatException("Couldn't parse stack trace line '$text'.");
+        throw new FormatException("Couldn't parse stack trace line '$text'.");
       }
       isCore = true;
     }