Detect if project directory was moved for venv reconstruction · astral-sh/uv#10895

(5 comments) (2 reactions) (0 assignees)Rust (84,934 stars) (3,111 forks)batch import

enhancementhelp wanted

Description

Summary

I just had an issue with pytest á la #7260. Turned out that because I had moved the project directory, the shebang in the "pytest" script in the venv was wrong, and apparently this meant that the command would fallthrough to the system-installed pytest which couldn't find my project or any of its dependencies, of course. uv sync would not detect this, but deleting .venv did the trick.

So I thought, since the location of the venv is hardcoded in the entrypoint scripts, it would be appropriate for uv to keep track of whether the venv location has changed. For example, it could go into the pyvenv.cfg file under a uv-venv-path variable or such. Then, if the actual path of the venv does not match this value, it would indicate to uv that the venv (or at least the entrypoints) should be reconstructed.

Example

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Contributor guide

Tech stack: pythonrustshell
Domain: toolingdeveloper experience
Issue type: feature
Difficulty: 3
Estimated time: 1-3 hours
Activity status: fresh
Clarity: clear
Prerequisites: basic knowledge of Python venvfamiliarity with uv's configuration files
Newbie friendliness: 70
Research direction: The issue suggests adding a `uv venv path` variable to `pyvenv.cfg` to detect if the project directory has moved. First, examine the current `pyvenv.cfg` file generated by uv (likely in `crates/uv configuration` or similar) to understand its format and how uv writes it. Look for where the venv is created and where entry points are generated. Then, identify where uv reads `pyvenv.cfg` to determine venv location. Consider implementing a check that compares the stored path with the actual path at startup, and if they differ, trigger a venv reconstruction. Check existing tests for venv handling to ensure new behavior is covered.