--- a/langtools/src/share/classes/com/sun/tools/javac/comp/Infer.java	Tue Mar 11 17:52:45 2014 -0700
+++ b/langtools/src/share/classes/com/sun/tools/javac/comp/Infer.java	Thu Mar 13 17:36:51 2014 +0000
@@ -2173,6 +2173,12 @@
             //back-door to infer
             return Infer.this;
         }
+
+        @Override
+        public String toString() {
+            return "Inference vars: " + inferencevars + '\n' +
+                   "Undet vars: " + undetvars;
+        }
     }
 
     final InferenceContext emptyContext = new InferenceContext(List.<Type>nil());