Add back print that got lost in last minute edit.

pkg/fletchc/lib/src/driver/developer.dart

Index: pkg/fletchc/lib/src/driver/developer.dart
diff --git a/pkg/fletchc/lib/src/driver/developer.dart b/pkg/fletchc/lib/src/driver/developer.dart
index c68db375fcfc3f2169d7746306b74237e9362483..eaa56f9b6c960a3f5f95ed247c59b126a61a6727 100644
--- a/pkg/fletchc/lib/src/driver/developer.dart
+++ b/pkg/fletchc/lib/src/driver/developer.dart
@@ -391,7 +391,7 @@ Future<int> run(SessionState state, {String testDebuggerCommands}) async {
   Future printTrace() async {
     String list = await session.list();
     String stackTrace = session.debugState.formatStackTrace();
-    if (!stackTrace.isEmpty) (stackTrace);
+    if (!stackTrace.isEmpty) print(stackTrace);
     if (!stackTrace.isEmpty) print(list);
   }