Hi, AbstractEnvironmentTestCase exists only in Pharo 8, tracking this with STON (from changes in Pharo 8) gives me tests that can no longer be loaded in Pharo 7 (or versions before that).
At least AbstractEnvironmentTestCase should be back ported to Pharo 7. Apart from that, I don't think this is a good change (since it breaks backwards compatibility too much). Why do all Smalltalk>>#at: references have to be removed ? The way I see it, Smalltalk>>#at: could be rewritten to dynamically use a different environment, if that is set up earlier, using a DynamicVariable. Similarly, #asClass could be implemented to follow the same path. Or am I wrong ? Sven