Look at UndeclaredVariableWarning. �The Squeak code isn't well favtored. �defaultAction needs to be decomposed further into a messageText implementation. �But basically I'd want the UndeclaredVariableWarning's messageText to provide the warning string. �So I could do e.g.

� � [Compiler evaluate: aString]

� � � � on: UndeclaredVariableWarning

� � � � do: [:ex| Transcript cr; show: ex messageText]