Register models when installing Panel from source code

I have an environment where I had Panel v0.14.1 installed from conda-forge. Everything works great. But when I pip install a specific branch of the source code, I get the following errors in my browser console:

Model 'panel.models.tabs.Tabs' does not exist. This could be due to a widget or a custom model not being registered before first usage.

Failed to load Bokeh session P6hW0mpHZ6ZUIIP2yW2QVNUMFL5V4mTix473eOifxwlO: Error: Model 'panel.models.tabs.Tabs' does not exist. This could be due to a widget or a custom model not being registered before first usage.

What do I need to do to register the models after pip installing Panel from source?

Try running python setup.py develop. You also need to have NodeJS installed (can be done with conda).

https://panel.holoviz.org/developer_guide/index.html#developing-custom-models