Unable to render dashboard (404) when using JupyterLab with Real Time Collaboration enabled

[jrouly]

Description

Voila extension is incompatible with JupyterLab "real time collaboration" (RTC) mode.

Reproduce

1. Run jupyterlab with jupyter-collaboration installed and enabled (--LabApp.collaborative=True).
2. Start up a notebook and hit the voila button to bring up a new side panel with the rendered dashboard.
3. Get a JupyterHub 404 error (404: Not Found You are requesting a page that does not exist!)

It seems like this is due to the URL for RTC notebooks including the prefix RTC: before the notebook filename (RTC:Untitled.ipynb).

I think this may be an underlying issue in jupyterlab (see this issue or this issue but I'm reporting it here for completeness.

Expected behavior

Dashboard renders.

Context

$ jupyter --version
Selected Jupyter core packages...
IPython          : 8.17.2
ipykernel        : 6.26.0
ipywidgets       : 8.1.1
jupyter_client   : 8.6.0
jupyter_core     : 5.5.0
jupyter_server   : 2.10.1
jupyterlab       : 4.0.8
nbclient         : 0.7.4
nbconvert        : 7.11.0
nbformat         : 5.9.2
notebook         : 7.0.6
qtconsole        : not installed
traitlets        : 5.13.0

If using JupyterLab

• JupyterLab version: 4.0.8

$ jupyter lab extension list
...
    voila.server_extension enabled
    - Validating voila.server_extension...
Package voila.server_extension took 0.0977s to import
      voila.server_extension  OK
    voila enabled
    - Validating voila...
Package voila took 0.0000s to import
      voila 0.5.5 OK

[jrouly]

Looks like upstream contributors view this as not their problem -- it's an issue in downstream extensions (like voila).