Issue 7911: unittest.TestCase.longMessage defaults to True for improved failure messages by default
diff --git a/Lib/unittest/case.py b/Lib/unittest/case.py
index bb337f1..227879c 100644
--- a/Lib/unittest/case.py
+++ b/Lib/unittest/case.py
@@ -245,7 +245,7 @@
     # objects used in assert methods) will be printed on failure in *addition*
     # to any explicit message passed.
 
-    longMessage = False
+    longMessage = True
 
     # This attribute sets the maximum length of a diff in failure messages
     # by assert methods using difflib. It is looked up as an instance attribute