Linux shutil.move between mountpoints as root does not retain ownership

GitHub fields:

assignee = None
closed_at = None
created_at = <Date 2016-08-04.20:44:42.234>
labels = ['type-feature', 'library']
title = 'Linux shutil.move between mountpoints as root does not retain ownership'
updated_at = <Date 2018-06-12.10:30:13.367>
user = 'https://bugs.python.org/jortbloem'

bugs.python.org fields:

activity = <Date 2018-06-12.10:30:13.367>
actor = 'giampaolo.rodola'
assignee = 'none'
closed = False
closed_date = None
closer = None
components = ['Library (Lib)']
creation = <Date 2016-08-04.20:44:42.234>
creator = 'jort.bloem'
dependencies = []
files = []
hgrepos = []
issue_num = 27687
keywords = []
message_count = 3.0
messages = ['272001', '272166', '272306']
nosy_count = 4.0
nosy_names = ['giampaolo.rodola', 'r.david.murray', 'ztane', 'jort.bloem']
pr_nums = []
priority = 'normal'
resolution = None
stage = None
status = 'open'
superseder = None
type = 'enhancement'
url = 'https://bugs.python.org/issue27687'
versions = ['Python 3.6']