Summary

Site-packages not found in system environment

I'm using ty on Ubuntu, where I want to use the system installation of python (/usr/bin/python3), but I get an
error whenever I am explicitly using it.

This error propogates all the way through to vscode - the server seems to function afterwards, but the error on
startup is a bit annoying.

Relevant Issues:

• support finding packages installed into Debian dist-packages directories #1323 looks like might be a downstream symptom of this.

Reproduction Steps

In a clean ubuntu docker docker run --rm -it ubuntu:

# Install ty
apt update ; apt install curl python3
curl -LsSf https://astral.sh/uv/install.sh | sh
source $HOME/.local/bin/env

# Create a test file
echo "" > test.py

# Run ty using the system python3 install
uvx ty check test.py --python /usr/bin/python3

This results in the following error:

ty failed
  Cause: Failed to discover the site-packages directory
  Cause: Invalid `--python` argument `/usr`: Could not find a `site-packages` directory for this Python installation/executable

interestingly this error only occurs if --python is provided - I haven't been able to decern which interpreter is being used if not provided (-vvv does not reveal this information - perhaps it should?).

Please note that this is NOT an issue in some other distros. I've tested using the following container mages and the same reproduction steps:

• alpine:latest (using apk instead of apt of course)
• archlinux:latest (using pacman instead of apt of course)

It seems that this is a uniquely debian (and debian-derivative) issue. Those distros are also weird about their python3 installation methods, so that makes sense.

It looks like site_packages.rs is only looking at sys.prefix / lib for site-packages, whereas on debian-derivative platforms it's located in sys.prefix / local / lib instead.

I would suggest a patch where local is optionally traversed during the site packages search. I might give it a try myself, but my rust is very... rusty... So I'm not confident that I'll be able to get it done properly.

Version

0.0.10