Application of config settings when installing package depends on content of uv cache

[smackesey]

We use uv to build the python environments that we run pyright against for our large codebase Dagster. Pyright environments do not handle Python import hooks correctly. It is therefore important that all editables installs in the environment use a "legacy" style, where the pth file contains a static path instead of an import hook.

Modern style:

### __editable__.foo-0.1.0.pth

import __editable___foo_0_1_0_finder; __editable___foo_0_1_0_finder.install()

Legacy style:

### __editable__.foo-0.1.0.pth

/path/to/foo

The way you force a legacy style when setuptools is used as build backend (which is what our packages use) is to pass editable_mode=compat as a config option. So this should work, and has worked in the past:

uv pip install --config-setting editable_mode=compat -e my_package

However, it seems like the cache is interfering in this command working properly. If the package has already been installed as editable without editable_mode=compat in one environment, then attempting to install it into a new environment with editable_mode=compat does not work.

uv version

uv 0.4.3 (Homebrew 2024-09-02)

Repro

Create a toy package foo:

mkdir foo
mkdir foo/foo
touch foo/__init__.py

cat >foo/pyproject.toml <<EOF
[project]
name = "foo"
version = "0.1.0"
EOF

Create a venv and install foo as an editable:

uv venv .venv-1
uv pip install --python=.venv-1/bin/python -e foo
cat .venv-1/lib/python3.12/site-packages/__editable__.foo-0.1.0.pth

# => import __editable___foo_0_1_0_finder; __editable___foo_0_1_0_finder.install()

Notice the content of the above pth is an import hook. That's expected.

But now create another venv and install foo as an editable using --config-setting editable_mode=compat. This should cause the content of the pth file to be a straight path instead of an import hook:

uv venv .venv-2
uv pip install --python=.venv-2/bin/python --config-setting editable_mode=compat -e foo
cat .venv-2/lib/python3.12/site-packages/__editable__.foo-0.1.0.pth

# => import __editable___foo_0_1_0_finder; __editable___foo_0_1_0_finder.install()

It looks like editable_mode=compat was ignored because we still have an import hook. Now repeat the above but with --no-cache:

uv venv .venv-3
uv pip install --python=.venv-3/bin/python --config-setting editable_mode=compat --no-cache -e foo
cat .venv-3/lib/python3.12/site-packages/__editable__.foo-0.1.0.pth

# => /path/to/foo

Now it works. So it looks like --config-setting editable_mode=compat is being passed through dependent on whether we are using the uv cache.

[charliermarsh]

Yeah, I think these definitely aren't included in the cache key.

[charliermarsh]

I think using --reinstall would also work here (or --reinstall-package foo).

[smackesey]

I think using --reinstall would also work here (or --reinstall-package foo).

Thanks, this is working and has enabled a workaround

[charliermarsh]

👍 I’m still looking into fixing it as part of some other caching improvements.