Can not use JupyterLab or Jupyter Notebooks with unsafe-eval turned off in Content Security Policy

[MikeMcGarry]

Describe the bug

Since 5 days ago the juptyer/notebook now uses a --development webpack build by default.

Unfortunately this is incompatible with a sensible Content Security Policy which does not have unsafe-eval included.

This is the line here: https://github.com/jupyter/notebook/blame/79fc76e890a8ec42f73a3d009e44ef84c14ef0d5/package.json#L20

And this is the merge request here: 79fc76e

To Reproduce
Steps to reproduce the behavior:

1. Install JupyterHub using the most recent version of the notebook
2. Visit your installation from any browser with a Content Security Policy that does not contain unsafe-eval. You will get nothing rendered when trying to run a notebook and the following console error

Expected behavior
No console error and everything works as expected.

Screenshots

Desktop (please complete the following information):

• Chrome
• Safari
• Edge

Additional context
Add any other context about the problem here.

[meeseeksmachine]

This issue has been mentioned on Jupyter Community Forum. There might be relevant details there:

https://discourse.jupyter.org/t/can-not-use-jupyterlab-or-jupyter-notebooks-with-unsafe-eval-turned-off-in-content-security-policy/10321/2

[MikeMcGarry]

Thank you for addressing this so quickly!