[BugFix] python collect_env.py and vllm collect-env compatibility with uv venv

[yankay]

Purpose

Fix: #24063

This PR fixes issues when running python collect_env.py and vllm collect-env inside a uv venv environment. The changes ensure correct environment detection and reporting, resolving errors and inconsistencies specific to uv venv setups.

Test Plan

uv venv
source .venv/bin/activate
uv pip install vllm --torch-backend=auto
vllm collect-env # or python vllm/collect_env.py

Test Result

After change:

(vllm) root@gpu-3090:~/oss/vllm# python vllm/collect_env.py
Collecting environment information...
uv is set

If no change, print error Could not collect pip list output (pip or uv module not available), the same as #24063

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Essential Elements of an Effective PR Description Checklist

• The purpose of the PR, such as "Fix some issue (link existing issues this PR will resolve)".
• The test plan, such as providing test command.
• The test results, such as pasting the results comparison before and after, or e2e results
• (Optional) The necessary documentation update, such as updating supported_models.md and examples for a new model.
• (Optional) Release notes update. If your change is user facing, please update the release notes draft in the Google Doc.

[gemini-code-assist]

Code Review

This pull request introduces a fix for detecting uv virtual environments in collect_env.py, which is a good improvement for compatibility. The new is_uv_venv function correctly checks for both the UV environment variable and the uv entry in pyvenv.cfg. I've suggested a small improvement to make the file parsing more robust and efficient.

[yankay]

Hi @DarkLight1337 @yihong0618,

Would it be possible to kindly ask you to review this PR?

[yihong0618]

Hi @DarkLight1337 @yihong0618,

Would it be possible to kindly ask you to review this PR?

I think its good

[DarkLight1337]

@mgoin is OOO so I'll just stamp this