`uv run` can fail to invoke `python`

[zanieb]

❯ uv run --isolated -v crates/uv-python/fetch-download-metadata.py
DEBUG uv 0.2.21
warning: `uv run` is experimental and may change without warning.
DEBUG Running `python crates/uv-python/fetch-download-metadata.py`
error: Failed to spawn: `python`
  Caused by: No such file or directory (os error 2)

[charliermarsh]

What's going on here? Hah

[charliermarsh]

Should we use the absolute path to the Python interpreter that we found?

[charliermarsh]

Or are we not adding it to PATH, maybe?

[charliermarsh]

Hmm, no, we do add the scripts directory to PATH which should include python...

[zanieb]

My suspicion here, without investigating further, is that we didn't create an environment (since there are no requirements) and tried to invoke python outside of one?

[charliermarsh]

Yeah this makes sense. It's kinda the same as https://github.com/astral-sh/uv/issues/4846.