In previous versions of attrs (verified in 16.3.0), you could get class attributes included in the auto-generated methods (__repr__, __eq__, et cetera) by setting these in the attrs decorator to the names of the attributes (with init=False). As of version 17.3.0, the attributes listed in these are simply deleted from the class definition, eliminating the whole reason for specifying them via these instead of in the class body, or automatically via type annotations. Attributes should only be deleted from the class definition if the attribute is an instance of whatever attr.ib returns, or at the very least, an option to not delete class attributes should be provided.

from attr import s, ib

@s(these=dict(something=ib(init=False)))
class test(object):
    something = 'xyzzy'

print(test())