Unable to configure jupyterlab_widgets / ipywidgets with jupiterWith

[dmayle]

Describe the bug Following the docs, I've generated a shell.nix and used generate-directory but the widgets won't load

To Reproduce

1. shell.nix

   let                                                                                                                                                                                                                                                                          
   jupyter = import (builtins.fetchGit {                                                                                                                                                                                                                                      
   url = https://github.com/tweag/jupyterWith;                                                                                                                                                                                                                              
   rev = "45f9a774e981d3a3fb6a1e1269e33b4624f9740e";                                                                                                                                                                                                                        
   }) {};                                                                                                                                                                                                                                                                     
   
   iPython = jupyter.kernels.iPythonWith {                                                                                                                                                                                                                                    
   name = "python";                                                                                                                                                                                                                                                         
   packages = p: with p; [                                                                                                                                                                                                                                                  
     beautifulsoup4                                                                                                                                                                                                                                                         
     ipywidgets                                                                                                                                                                                                                                                             
     matplotlib                                                                                                                                                                                                                                                             
     Keras                                                                                                                                                                                                                                                                  
     pillow                                                                                                                                                                                                                                                                 
     tensorflow                                                                                                                                                                                                                                                             
     tqdm                                                                                                                                                                                                                                                                   
     jupyterlab-widgets                                                                                                                                                                                                                                                     
   ];                                                                                                                                                                                                                                                                       
   };                                                                                                                                                                                                                                                                         
   
   golang = jupyter.kernels.gophernotes {                                                                                                                                                                                                                                     
   name = "Go";                                                                                                                                                                                                                                                             
   };                                                                                                                                                                                                                                                                         
   
   jupyterEnvironment =                                                                                                                                                                                                                                                       
   jupyter.jupyterlabWith {                                                                                                                                                                                                                                                 
     kernels = [ iPython golang ];                                                                                                                                                                                                                                          
     directory = /home/doug/src/ml-playground/jupyterlab;                                                                                                                                                                                                                 
   };                                                                                                                                                                                                                                                                       
   in                                                                                                                                                                                                                                                                           
   jupyterEnvironment.env

   Run generate-directory jupyterlab_widgets Enter this into a jupyterlab cell:

   import jupyterlab_widgets
   from ipywidgets import interact, interactive, fixed, interact_manual
   import ipywidgets as widgets
   def f(x):
   return x
   interact(f, x=10)

Expected behavior The cell output should be an interactive slider

Environment

• Debian latest with home manager
• Version of the code: (git hash in shell.nix)

Additional context

doug@doug-laptop:~/src/ml-playground$ jupyter-labextension list
JupyterLab v3.1.6
Other labextensions (built into JupyterLab)
   app dir: /nix/store/wijndwf354w2i7fx7j30w7pgl3vqh4f0-jupyterlab
        jupyterlab_widgets v0.3.1 enabled OK

[garbas]

In next version we wont support generate-directory command anymore, but we will focus on packaging extensions with Nix.