I think this is an inherent problem with dynamically typed languages. There are no reliable refactoring tools so even the slightest non compatible change can be

I think this is an inherent problem with dynamically typed languages. There are no reliable refactoring tools so even the slightest non compatible change can be lurking anywhere for years. And with things like meta programming, monkey patching and relying on private members, even changes that are supposed to be backwards compatible might end up to not be.