poetry install generated .pth files don't use drive letter for mapped network drives

• Poetry version: 1.7.1
• Python version: 3.12.1
• OS version and name: Windows 11

• I am on the latest stable Poetry version, installed using a recommended method.
• I have searched the issues of this repo and believe that this is not a duplicate.
• I have consulted the FAQ and blog for any relevant entries or release notes.
• If an exception occurs when executing a command, I executed it again in debug mode (-vvv option) and have included the output below.

Issue

possibly related to https://github.com/python-poetry/poetry/issues/4327 https://github.com/python-poetry/poetry/issues/959

I have a poetry project on a mapped network drive (z:) in Windows. When I run poetry install, the .venv\Lib\site-packages\app.pth file that is created uses the UNC path instead of the drive path:

app.pth
//server/share/app

But it should be:

Z:\app

This specifically caused problems for me because both the UNC path and the Z:\ path ended up in sys.path in my virtualenv:

Python 3.12.1 (tags/v3.12.1:2305ca5, Dec  7 2023, 22:03:25) [MSC v.1937 64 bit (AMD64)] on win32
>>> import sys
>>> sys.path
['Z:\\app\\.venv', 'Z:\\app\\.venv\\Lib\\site-packages', '\\\\server\\share\\app']

This slowed Pylance to a crawl in VS Code. Might be a bug in Pylance but it basically made it re-index my project continually, as it presumably tried to reconcile duplicate search paths.

Manually changing the app.pth path to use Z:\ and restarting VS Code fixed all issues.

Curiously, direct_url.json appears to use the correct path:

.venv/Lib/site-packages/app-0.0.1-dist-into/direct_url.json
{"dir_info": {"editable": true}, "url": "file:///Z:/app"}

Start by reproducing poetry install for the reported Windows 11 project on mapped drive Z:, then trace how the editable install writes .venv\Lib\site-packages\app.pth and compare it with the direct_url.json path. Done means the .pth file preserves the drive-letter path rather than the UNC path, avoiding duplicate entries in sys.path.