Guard against deletion of the current environment

[zanieb]

For example, uv venv will happily clear the current virtual environment.

This is most notably an issue when uv is installed in that environment.

[MichaReiser]

This also an issue on Windows where the operation fails.

uv venv
Using Python 3.12.2 interpreter at C:\Users\Micha\AppData\Local\Programs\Python\Python312\python.exe
Creating virtualenv at: .venv
uv::venv::creation

  × Failed to create virtualenv
  ├─▶ failed to remove directory `.venv`
  ╰─▶ Access is denied. (os error 5)

[charliermarsh]

@gaborbernat -- just curious, do virtualenv do anything special here (e.g., if you try to create a virtualenv with --clear, and the virtualenv.exe you're running is in the directory that needs to be removed)?

[gaborbernat]

Nothing at all: https://github.com/pypa/virtualenv/blob/5cd543f/src/virtualenv/create/creator.py#L155-L157

[charliermarsh]

Thanks!

[bersbersbers]

Here's another/similar issue regarding uv trying to delete the current environment. I think the main issue is the mismatch between some leftover .python-version that I had and the (new) .venv. But ideally, uv would be smart enough to detect that it is currently running from said .venv, and should not try deleting it.

bug.bat:

@echo off
if not exist c:\ws\bug mkdir c:\ws\bug
pushd c:\ws\bug

if exist .venv rmdir .venv /s/q
echo 3.12.3 > .python-version
echo [project] > pyproject.toml
echo name = "Bug" >> pyproject.toml
echo version = "1" >> pyproject.toml

python -m venv .venv
call .venv\scripts\activate

pip install uv
uv sync --verbose

pause

Output:

Collecting uv
  Using cached uv-0.4.20-py3-none-win_amd64.whl.metadata (11 kB)
Using cached uv-0.4.20-py3-none-win_amd64.whl (14.2 MB)
Installing collected packages: uv
Successfully installed uv-0.4.20
DEBUG uv 0.4.20
DEBUG Found project root: `c:\ws\bug`
DEBUG No workspace root found, using project root
DEBUG Reading requests from `c:\ws\bug\.python-version`
DEBUG The virtual environment's Python version does not satisfy `Python 3.12.3`
DEBUG Searching for Python 3.12.3 in managed installations, system path, or `py` launcher
DEBUG Searching for managed installations at `C:\Users\bers\AppData\Roaming\uv\python`
DEBUG Found managed installation `cpython-3.12.3-windows-x86_64-none`
DEBUG Found `cpython-3.12.3-windows-x86_64-none` at `C:\Users\bers\AppData\Roaming\uv\python\cpython-3.12.3-windows-x86_64-none\python.exe` (managed installations)
Using CPython 3.12.3
error: failed to remove directory `c:\ws\bug\.venv`
  Caused by: Access is denied. (os error 5)
Press any key to continue . . .