This is in Pharo 3, isn't it ?

There are currently bugs with Opal's exception handing in Pharo 3.0. It was fixed then some other changes broke it again. So yeah it is known. You might have bug with:
OCShadowVariableWarning.�
OCUndeclaredVariableWarning.�
OCUninitializedVariableWarning.�
OCUnusedVariableWarning.�
OCUnknownSelectorWarning.


2013/8/11 St�phane Ducasse <stephane.ducasse@inria.fr>
Hi guys

Is it a know bug?

| selector superClasses |
� � � � selector := aMethodDefinition selector.
� � � � superClasses := aMethodDefinition realClass allSuperclasses.
� � � � result := OrderedCollection new.
� � � � (superClasses select: [ :eachClass | eachClass hasProtocolFor: selector])
� � � � � � � � do: [ :eachClass | (eachClass includesSelector: selector)
� � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � ifTrue: [ result add: (self whichCategoryIncludesSelector: selector)]].
� � � � ^ result asBag

adds result

result | selector superClasses |
� � � � selector := aMethodDefinition selector.
� � � � superClasses := aMethodDefinition realClass allSuperclasses.
� � � � result := OrderedCollection new.
� � � � (superClasses select: [ :eachClass | eachClass hasProtocolFor: selector])
� � � � � � � � do: [ :eachClass | (eachClass includesSelector: selector)
� � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � ifTrue: [ result add: (self whichCategoryIncludesSelector: selector)]].
� � � � ^ result asBag

stef