It turns out that in Pharo we use Association and in Squeak we use ReadOnlyVariableBinding; by changing VariableNode >> #isSharedVarNode

You should think about cleaning that up... in the SystemDictonary, old classes are ReadOnlyVariableBinding, new ones are Associations. The code to make a binding into a ReadOnlyVariableBinding is never called... Marcus -- Marcus Denker -- http://marcusdenker.de