Hey Maxime, The let form was mostly included because, if possible, we should pull the value of `beets-python-version` from the version of python used for beets (because this implementation currently relies on a hardcoded and versioned library path in `lib/python3.9/site-packages`, it will require maintenance that could otherwise be avoided if we pulled the version from python directly. However, I don't know how to do that, or if that is possible. If it's not something easily doable, then I will remove the let form for now, and see about improving it in the future. As for the issue of other python libraries possibly polluting the beets install, AFAIK beets looks for a folder named `beetsplug` in the PYTHONPATH and only considers files beneath it. I think we can safely avoid isolating the beets plugins; Whether this is the route Guix wants to go is something I think should ideally be standardized across all packages if possible (maybe an email thread on guix-devel?), because the main channel as a whole will be more maintainable if we can come to some kind of agreement. Let me know what You think. -- Christopher Rodriguez