In 3.4 with or without the recent update that improves the ClassBuilder 
there seems to be a problem relating to weak subclasses.

My testcase is to recompile Array. This fails with the attached 
debuglog because the code checks to see if the type of the WeakArray 
subclass of Array is the same as the type of the intended new class 
Array. It gets a bit hard to describe but I hope that makes sense.
My guess (and it's only a guess for now) is that the code
	newType ~~ #normal ifTrue:
		["And check if the immediate subclasses of oldClass can keep its 
layout"
		oldClass subclassesDo:[:sub|
			oldType _ sub typeOfClass.
			oldType == newType ifFalse: [
				self error: sub name,' cannot be recompiled'.
				^ false]]].
probably ought to try to understand that #weak is a subform of 
#variable. Or whatever.
>
tim
-- 
tim at sumeru.stanford.edu