Group Policy Blocks UV Tool from Accessing Python Interpreter

[IliasAarab]

Description:

I am encountering a persistent issue with the UV tool where it fails to access the Python interpreter due to a group policy restriction. This problem occurs not only when adding packages but also when running scripts.

Error Details:

• Command: uv add faker and uv run src/uv_prj/__init__.py

• Error Message:

  error: Failed to query Python interpreter at `\\?\C:\Users\aarabil\Desktop\quick_runs\uv_prj\.venv\Scripts\python.exe`
  Caused by: This program is blocked by group policy. For more information, contact your system administrator. (os error 1260)

Steps to Reproduce:

1. Create a new virtual environment using uv.
2. Attempt to add a package using uv add faker.
3. Attempt to run a script using uv run src/uv_prj/__init__.py.

Expected Behavior:

The UV tool should be able to add packages and run scripts without encountering errors related to the Python interpreter.

Actual Behavior:

Both operations fail with an error indicating that the Python interpreter is blocked by group policy.

Environment:

• OS: Windows
• UV Tool Version: 0.3.2 (c5440001c 2024-08-23) (installed with pip within a Conda env)
• Python Version: 3.12 (within a Conda env)
• Virtual Environment Location: C:\Users\aarabil\Desktop\quick_runs\uv_prj\.venv\

Additional Information:

The error suggests that the group policy settings on the system are preventing the UV tool from accessing the Python interpreter. I am wondering how others deal with this issue within a corporate environment?

[samypr100]

Do you happen to know what is the group policy in effect (e.g. is it a built-in to gpedit.exe) and how it's configured? I could tinker with gpedit.exe, but it's hard to reproduce without knowing the exact configuration.

[IliasAarab]

@samypr100 thank you for the quick response. Unfortunately, I don't know any of the inner details of the policy. What I do know is that is seems that executables can not be executed when they are stored in c/users/<username>/. In contrast, I can run uv when i create a new project in c/conda/envs (although this is obviously not the right place to initialize projects).

[samypr100]

Maybe the policy only allows certain locations for executables? The best bet is to look at the policy yourself e.g. via command prompt running something like gpresult /h %USERPROFILE%\gp.html and see if there's something in there that matches what you're seeing. Note, DO NOT attach that file here.

[contang0]

Maybe the policy only allows certain locations for executables? The best bet is to look at the policy yourself e.g. via command prompt running something like gpresult /h %USERPROFILE%\gp.html and see if there's something in there that matches what you're seeing. Note, DO NOT attach that file here.

I have the same issue and you're correct. If, for example, uv created the environments in C:\Mambaforge\envs, I believe it would work. I thought setting UV_PROJECT_ENVIRONMENT to C:\Mambaforge\envs might work, but unfortunately it still creates the .venv folder next to the project files.

C:\Users\user\Desktop\Projects\test>echo %UV_PROJECT_ENVIRONMENT%
C:\Mambaforge\envs

C:\Users\user\Desktop\Projects\test>uv init
Initialized project `test`

C:\Users\user\Desktop\Projects\test>uv run hello.py
Using Python 3.9.7 interpreter at: C:\Mambaforge\python.exe
Creating virtualenv at: .venv
error: Failed to spawn: `python`
  Caused by: This program is blocked by group policy. For more information, contact your system administrator. (os error 1260)

C:\Users\user\Desktop\Projects\test>dir
 Volume in drive C is Windows

 Directory of C:\Users\user\Desktop\Projects\test

04/09/2024  02:03 PM    <DIR>          .
12/08/2024  05:29 PM    <DIR>          ..
04/09/2024  02:03 PM    <DIR>          .venv
04/09/2024  02:03 PM                82 hello.py
04/09/2024  02:03 PM               149 pyproject.toml
04/09/2024  02:03 PM                 0 README.md
04/09/2024  02:03 PM               110 uv.lock
               4 File(s)            341 bytes
               3 Dir(s)  292,483,772,416 bytes free

@zanieb is this the expected behavior once UV_PROJECT_ENVIRONMENT is set?

[zanieb]

@contang0 I couldn't reproduce that on my machine

❯ uv init --no-workspace example
Initialized project `example` at `/Users/zb/workspace/uv/example`
❯ cd example
❯ ls
README.md   hello.py    pyproject.toml
❯ UV_PROJECT_ENVIRONMENT=/tmp/foo uv run hello.py
Using Python 3.11.7
Creating virtualenv at: /tmp/foo
Hello from example!
❯ ls -lah
total 32
drwxr-xr-x   7 zb  staff   224B Sep  4 08:40 .
drwxr-xr-x  57 zb  staff   1.8K Sep  4 08:39 ..
-rw-r--r--   1 zb  staff     4B Sep  4 08:39 .python-version
-rw-r--r--   1 zb  staff     0B Sep  4 08:39 README.md
-rw-r--r--   1 zb  staff    85B Sep  4 08:39 hello.py
-rw-r--r--   1 zb  staff   153B Sep  4 08:39 pyproject.toml
-rw-r--r--   1 zb  staff   114B Sep  4 08:40 uv.lock

[contang0]

It seems like this is a Windows-specific issue.

[zanieb]

While I agree for the policy part, that doesn't make sense for the UV_PROJECT_ENVIRONMENT behavior — path determination for the environment should not be platform specific (and is tested on Windows in CI).

[contang0]

I upgraded to the latest version (0.4.4) and now I see slightly different things.

Looks like I misunderstood how UV_PROJECT_ENVIRONMENT works. It defines one venv for all projects, whereas I need a way to specify the root directory where separate venvs for each of my projects will reside. Unless there's a smarter way to get around this group policy.

C:\Users\user\Desktop\Projects\test2>uv --version
uv 0.4.4 (3d75df6ab 2024-09-04)

C:\Users\user\Desktop\Projects\test2>echo %UV_PROJECT_ENVIRONMENT%
C:\Mambaforge\envs

C:\Users\user\Desktop\Projects\test2>uv init
Initialized project `test2`

C:\Users\user\Desktop\Projects\test2>uv run hello.py
warning: Ignoring existing virtual environment linked to non-existent Python interpreter: C:\Mambaforge\envs\Scripts\python.exe
Using Python 3.9.7 interpreter at: C:\Mambaforge\python.exe
error: failed to remove directory `C:\Mambaforge\envs`
  Caused by: Access is denied. (os error 5)

[zanieb]

@contang0 that is explicitly not supported, please see https://github.com/astral-sh/uv/pull/6834 and #1495 — let's stop talking about unrelated questions in this issue though.

[IliasAarab]

Maybe the policy only allows certain locations for executables? The best bet is to look at the policy yourself e.g. via command prompt running something like gpresult /h %USERPROFILE%\gp.html and see if there's something in there that matches what you're seeing. Note, DO NOT attach that file here.

Thanks! I cannot fully understand the output, but can understand that the policy is blocking executables on certain drives and certain locations. The easiest solution for me, currently, is to constraint new projects that are initialized with uv to live within the permitted policy locations. #1495 is an interesting proposal, and as far as I understand, would mimic the current behaviour of conda.