venv module produces spurious warning that location has moved

[layday]

BPO	46171
Nosy	@pfmoore, @vsajip, @tjguk, @zware, @eryksun, @zooba, @FFY00, @layday

^{Note: these values reflect the state of the issue at the time it was migrated and might not reflect the current state.}

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GitHub fields:

assignee = None
closed_at = None
created_at = <Date 2021-12-24.09:29:51.804>
labels = ['type-bug', '3.9', '3.10', '3.11', 'library', 'OS-windows']
title = 'venv module produces spurious warning that location has moved'
updated_at = <Date 2021-12-31.16:46:09.275>
user = 'https://github.com/layday'

bugs.python.org fields:

activity = <Date 2021-12-31.16:46:09.275>
actor = 'eryksun'
assignee = 'none'
closed = False
closed_date = None
closer = None
components = ['Library (Lib)', 'Windows']
creation = <Date 2021-12-24.09:29:51.804>
creator = 'layday'
dependencies = []
files = []
hgrepos = []
issue_num = 46171
keywords = []
message_count = 7.0
messages = ['409135', '409144', '409145', '409256', '409282', '409420', '409424']
nosy_count = 8.0
nosy_names = ['paul.moore', 'vinay.sajip', 'tim.golden', 'zach.ware', 'eryksun', 'steve.dower', 'FFY00', 'layday']
pr_nums = []
priority = 'normal'
resolution = None
stage = None
status = 'open'
superseder = None
type = 'behavior'
url = 'https://bugs.python.org/issue46171'
versions = ['Python 3.9', 'Python 3.10', 'Python 3.11']

Linked PRs

• gh-90329: Add _winapi.GetLongPathName and GetShortPathName and use in venv to reduce warnings #117817
• [3.12] gh-90329: Add _winapi.GetLongPathName and GetShortPathName and use in venv to reduce warnings (GH-117817) #117898

[layday]

After 6811fda
the venv module produces spurious warnings for venv paths which contain
DOS-encoded parts e.g. "USER~1" in "C:\Users\USER~1".
tempfile.gettempdir() returns legacy paths like these for
user temp dirs.

MRE:

python -c "import tempfile
import venv

venv.create(tempfile.mkdtemp())"
Actual environment location may have moved due to redirects, links or junctions.
Requested location: "C:\Users\RUNNER~1\AppData\Local\Temp\tmpfoobar\Scripts\python.exe"
Actual location:    "C:\Users\runneradmin\AppData\Local\Temp\tmpfoobar\Scripts\python.exe"

[eryksun]

There's no point to making the user worry about short names, symlinks, or non-canonical mount points in the filesystem path of a virtual environment. It's still accessible where the user expects to find it. The problem for bpo-45337 is filesystem redirection in UWP apps, in particular for files and directories created under "%USERPROFILE%\AppData". The warning could be limited to just paths in that tree.

[eryksun]

There's still the problem of the system using short names in %TEMP%, since by default that's under "%USERPROFILE%\AppData". Either an exception could be made for the temp directory, since it's never redirected (AFAIK), or support could be added for GetLongPathNameW() [1] as nt._getlongpathname().

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[1] https://docs.microsoft.com/en-us/windows/win32/api/fileapi/nf-fileapi-getlongpathnamew