ObjectAsMethodWrapper's test suite breaks ObjectAsMethodWrapperDummy's organization - its #foo and #bar methods disappear even though the method dictionary still has them. As a result, after you've run OAMW's tests, you can't do anything with the OAMW PackageInfo - you can't check to see what changes you made, save the new mcz, etc. The bug affects both Squeak and Pharo: when you try do anything with the package you get a MNU because the MethodReferences to ObjectAsMethodWrapperDummy >> #foo and #bar have nils for their category instvars. The attached mcz changes the _ assignments to := ones so Pharo folk can run the tests. I don't have a solution yet, but wanted to raise the issue. It looks like PackageInfo possibly isn't catching the AddEvent sent by ClassDescription >> #addSelector:withMethod:notifying: but I'm just guessing: I don't know enough about this part of the system. frank