When using setup.py,

pip install -e .

creates a my_app.egg-info directory containing a PKG-INFO file.

After moving to pyproject.toml, the same install procedure doesn’t update or remove that directory.

It seems that

importlib.metadata.version("my_app")

uses PKG-INFO to determine the package version, which results in a wrong reported version in our setup.

This is fixed by removing the outdated directory manually.

This caught us by surprise and I’m wondering if this is expected behaviour or if a bug should be opened somewhere to somehow fix this. I’d be happy if someone could shed light on this as I don’t know exactly where to look to figure it out.