urllib2.urlopen fails if http_proxy(s) is set to a sock5 proxy

GitHub fields:

assignee = None
closed_at = None
created_at = <Date 2018-07-04.04:33:55.500>
labels = ['type-bug', 'library']
title = 'urllib2.urlopen fails if http_proxy(s) is set to a sock5 proxy'
updated_at = <Date 2019-05-04.15:34:53.152>
user = 'https://bugs.python.org/TL2'

bugs.python.org fields:

activity = <Date 2019-05-04.15:34:53.152>
actor = 'Daniel Wallace'
assignee = 'none'
closed = False
closed_date = None
closer = None
components = ['Library (Lib)']
creation = <Date 2018-07-04.04:33:55.500>
creator = 'T L2'
dependencies = []
files = []
hgrepos = []
issue_num = 34038
keywords = []
message_count = 2.0
messages = ['321010', '341387']
nosy_count = 2.0
nosy_names = ['T L2', 'Daniel Wallace']
pr_nums = []
priority = 'normal'
resolution = None
stage = None
status = 'open'
superseder = None
type = 'behavior'
url = 'https://bugs.python.org/issue34038'
versions = ['Python 2.7']