Fix bug 6467:

runtime/vm/dart_api_impl.cc

 // Copyright (c) 2012, 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.
 
 #include "include/dart_api.h"
 
 #include "vm/bigint_operations.h"
 #include "vm/class_finalizer.h"
 #include "vm/compiler.h"
 #include "vm/dart.h"
@@ skipping 721 matching lines @@
 
 // --- Initialization and Globals ---
 
 DART_EXPORT const char* Dart_VersionString() {
   return Version::String();
 }
 
 DART_EXPORT bool Dart_Initialize(Dart_IsolateCreateCallback create,
                                  Dart_IsolateInterruptCallback interrupt,
                                  Dart_IsolateShutdownCallback shutdown) {
-  return Dart::InitOnce(create, interrupt, shutdown);
+  const char* err_msg = Dart::InitOnce(create, interrupt, shutdown);
+  if (err_msg != NULL) {
+    OS::PrintErr("Dart_Initialize: %s\n", err_msg);
+    return false;
+  }
+  return true;
 }
 
 DART_EXPORT bool Dart_SetVMFlags(int argc, const char** argv) {
   return Flags::ProcessCommandLineFlags(argc, argv);
 }
 
 DART_EXPORT bool Dart_IsVMFlagSet(const char* flag_name) {
   if (Flags::Lookup(flag_name) != NULL) {
     return true;
   }
@@ skipping 3739 matching lines @@
   }
   {
     NoGCScope no_gc;
     RawObject* raw_obj = obj.raw();
     isolate->heap()->SetPeer(raw_obj, peer);
   }
   return Api::Success(isolate);
 }
 
 }  // namespace dart