Finding errors in evaluated expressions
Whenever you use the Edit menu options Execute, Display, or Inspect, the message Doit is sent, usually to the object nil. Thus, selecting the message UndefinedObject>>#Doit from the message stack displays, in highlighted text, the expression that triggered the debugger. The message below the lowest ExceptionalEvent>>#signalWith: and above UndefinedObject>>#Doit in the stack usually contains the expression that caused the error.
Last modified date: 01/29/2015