There’s no error in the original example; in Python, the ability to participate in inheritance diamonds with arbitrary other classes is a feature which must be

There’s no error in the original example; in Python, the ability to participate in inheritance diamonds with arbitrary other classes is a feature which must be explicitly documented and maintained. James Knight wrote a really good piece on this many years ago: https://fuhm.net/super-harmful/ https://fuhm.net/super-harmful/ The solution is just to avoid inheritance. It’s full of terrible pitfalls in most languages, but Python more than most.