The cmp argument to attr.s() and attr.ib() is now deprecated.
Please use eq to add equality methods (__eq__ and __ne__) and order to add ordering methods (__lt__, __le__, __gt__, and __ge__) instead – just like with dataclasses.
Both are effectively True by default but it's enough to set eq=False to disable both at once.
Passing eq=False, order=True explicitly will raise a ValueError though.
Since this is arguably a deeper backward-compatibility break, it will have an extended deprecation period until 2021-06-01.
After that day, the cmp argument will be removed.
attr.Attribute also isn't orderable anymore.