Nice! I was thinking about something like that too. E.g. building symlinks for all the deps into a local directory and use it as PYTHONPATH. I tried it with your example on GitHub and it worked. And then if all the developers are using something like direnv[1] this PYTHONPATH variable could easily be set for everyone.
How do you manage dependencies for the fine-grained Bazel targets (like py_library)? Do you write them manually or using some language-specific tools like Gazelle? If you do use the tool, do you have anything in place to automate it?
Couple years ago I had a pretty bad experience with people complaining about having to execute Gazelle manually. In my ideal world view I'd want to add an import statement in code and just run `bazel build`. So I ended having a wrapper that would run Gazelle before running Bazel all the time, but it slowed thing down quite a bit, because it was doing a lot of unnecessary work.
[1]: https://direnv.net
