better debugging information

commands.py

@@ -483,7 +483,8 @@ class Choice(Command):
             return default
         else:
             raise ConfigError(
-                "Default on Enter - value not a possible option " +
+                "Default on Enter - value '" + default
+                + "' not a possible option " +
                 "(" + self.name + " in " + self.reason.name + ")")
 
     def sortOptions(self):
@@ -751,6 +752,7 @@ class Choice(Command):
             except self.AgainException:
                 continue
 
+
 class Default(Command):
     """A default value is saved.