os.makedirs fails on long-path UNC-paths if it is the first sub-folder

GitHub fields:

assignee = None
closed_at = None
created_at = <Date 2020-09-03.19:28:37.918>
labels = ['type-bug', '3.8', 'OS-windows']
title = 'os.makedirs fails on long-path UNC-paths if it is the first sub-folder'
updated_at = <Date 2020-09-03.22:01:32.759>
user = 'https://github.com/Safihre'

bugs.python.org fields:

activity = <Date 2020-09-03.22:01:32.759>
actor = 'eryksun'
assignee = 'none'
closed = False
closed_date = None
closer = None
components = ['Windows']
creation = <Date 2020-09-03.19:28:37.918>
creator = 'Safihre'
dependencies = []
files = []
hgrepos = []
issue_num = 41705
keywords = []
message_count = 2.0
messages = ['376312', '376326']
nosy_count = 6.0
nosy_names = ['paul.moore', 'tim.golden', 'zach.ware', 'eryksun', 'steve.dower', 'Safihre']
pr_nums = []
priority = 'normal'
resolution = None
stage = None
status = 'open'
superseder = None
type = 'behavior'
url = 'https://bugs.python.org/issue41705'
versions = ['Python 3.8']