abc module fails to reject instantiation of some multiply-inheriting classes that fail to implement abstract methods #72723

assignee = None
closed_at = <Date 2016-10-26.00:44:33.168>
created_at = <Date 2016-10-25.23:42:42.012>
labels = ['3.7', 'type-bug', 'library']
title = 'abc module fails to reject instantiation of some multiply-inheriting classes that fail to implement abstract methods'
updated_at = <Date 2016-10-26.00:44:33.166>
user = 'https://github.com/nathanielmanistaatgoogle'

activity = <Date 2016-10-26.00:44:33.166>
actor = 'r.david.murray'
assignee = 'none'
closed = True
closed_date = <Date 2016-10-26.00:44:33.168>
closer = 'r.david.murray'
components = ['Library (Lib)']
creation = <Date 2016-10-25.23:42:42.012>
creator = 'Nathaniel Manista'
dependencies = []
files = ['45226']
hgrepos = []
issue_num = 28537
keywords = []
message_count = 2.0
messages = ['279465', '279473']
nosy_count = 4.0
nosy_names = ['aleax', 'r.david.murray', 'cvrebert', 'Nathaniel Manista']
pr_nums = []
priority = 'normal'
resolution = 'duplicate'
stage = 'resolved'
status = 'closed'
superseder = '5996'
type = 'behavior'
url = 'https://bugs.python.org/issue28537'
versions = ['Python 2.7', 'Python 3.3', 'Python 3.4', 'Python 3.5', 'Python 3.6', 'Python 3.7']