Developer installation with JupyterLab 3.0

[jpanetta]

I couldn't get the new instructions for setting up a developer installation in JupyterLab 3.0 working. I tried:

cd pythreejs
pip3 install -e . # installs `manager` and `datawidgets` prebuilt labextensions but not the pythreejs one
jupyter labextension develop . --overwrite # fails due to missing package.json
cd js
jupyter labextension build .
jupyter labextension develop . --overwrite # fails due to missing setup.py

Should this have worked? What are the current recommended steps? I see in the new extension cookiecutter both setup.py and package.json are in the same directory, where labextension develop expects them.

I was able to install with jupyter labextension install . within the js directory, but I would like a development setup.

[6A61736F6E206E61646572]

@jpanetta Did you end up figuring this out?