The traversal of MROs when using multiple inheritance was backward: If you defined a class ``C`` that subclasses ``A`` and ``B`` like ``C(A, B)``, ``attrs`` would have collected the attributes from ``B`` *before* those of ``A``. This is now fixed and means that in classes that employ multiple inheritance, the output of ``__repr__`` and the order of positional arguments in ``__init__`` changes. Due to the nature of this bug, a proper deprecation cycle was unfortunately impossible.