MagmaWbClassBuilder >> migrateFromTarget:to: starts with a "self halt". I assume that is just some debug leftover. Am I right?
In MagmaSession class >> cleanUp occurence of "(PointerFinder pointersTo: each)" should be replaced with "each pointersTo", since PointerFinder is deprecated (I'm talking Pharo 1.3 here).
I made a patch.