bug#52139: jupyter trying to modify /gnu/store

[Lars-Dominik Braun]

Hi,

> I can’t reproduce it with: […]
I cannot reproduce it either and this migration should not happen™,
because the phase 'disable-migration should disable it. (See
/gnu/store/8ncan0ipzb240h23fwfspdhrzkzdw277-python-jupyter-core-4.7.1/lib/python3.8/site-packages/jupyter_core/application.py:145).

Alexander: Does this file exists for you too?

    guix shell python-notebook -- sh -c "stat \$JUPYTER_CONFIG_DIR/migrated"

> The JUPYTER_CONFIG_DIR search path was added to ‘python-jupyter-core’ in
> commit 1683e9d9677d54f695a54fc44ed309287989fc34.  Lars, what are you
> thoughts?
Please *do not* remove this environment variable. It is required, because
packages like jupyterlab drop a config file into this directory. Without
it the jupyterlab extension will not be loaded by default and a simple
`guix shell python-jupyterlab -- jupyter lab` will not work.

Cheers,
Lars