Class UsageError

              object --+                
                       |                
exceptions.BaseException --+            
                           |            
        exceptions.Exception --+        
                               |        
        exceptions.StandardError --+    
                                   |    
                exceptions.TypeError --+
                                       |
                                      UsageError

Used to report illegal hunt options, or invalid combinations of options.

When this is caught by the main cmdline driver, the error message will be printed and the usage message displayed.