Switch to JupyterLab 4

[fcollonval]

Fixes https://github.com/jupyterlab/jupyterlab-demo/issues/49

https://mybinder.org/v2/gh/jupyterlab/jupyterlab-demo/lab-4.0?urlpath=lab

@krassowski I was looking at modernizing this package by merging the opened PRs.

I will left aside the upgrade to 4 to be the focus of this branch. Let me know if I can help.

:warning: this removes the R kernel.

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[krassowski]

This is odd:

+ jupyter lab workspaces import .binder/workspace.json
[LabWorkspaceImportApp] Workspace could not be exported:
Workspace metadata ID mismatch: expected '/lab' got '/lab'

Seems that the check prepends /: https://github.com/jupyterlab/jupyterlab_server/blob/4978e2422d8fbb9094af9be84190872f0aed5fea/jupyterlab_server/workspaces_handler.py#L153-L156

[krassowski]

Giving up on xeus stack:

Could not solve for environment specs
The following packages are incompatible
├─ xeus-cling 0.15.1**  is installable and it requires
│  └─ cppzmq >=4.9.0,<4.10.0a0 , which can be installed;
└─ xleaflet   is uninstallable because there are no viable options
   ├─ xleaflet [0.10.0|0.5.0|...|0.9.0] would require
   │  └─ xeus [>=0.17.0,<0.18.0a0 |>=0.18.1,<0.19.0a0 |>=0.19.1,<0.20.0a0 |>=0.20.0,<0.21.0a0 |>=0.21.1,<0.22.0a0 ], which requires
   │     └─ cppzmq >=4.3.0,<4.4.0a0 , which conflicts with any installable versions previously reported;
   ├─ xleaflet 0.11.0 would require
   │  └─ xeus >=0.23.3,<0.24.0a0  but there are no viable options
   │     ├─ xeus [0.17.0|0.18.1|...|0.23.5], which cannot be installed (as previously explained);
   │     ├─ xeus [0.23.10|0.23.12|...|0.24.1] would require
   │     │  └─ cppzmq >=4.6.0,<4.7.0a0 , which conflicts with any installable versions previously reported;
   │     └─ xeus [0.23.5|0.23.6] would require
   │        └─ cppzmq >=4.4.1,<4.5.0a0 , which conflicts with any installable versions previously reported;
   ├─ xleaflet 0.11.1 would require
   │  └─ xeus >=0.23.14,<0.24.0a0 , which cannot be installed (as previously explained);
   ├─ xleaflet [0.11.1|0.11.2] would require
   │  └─ xeus >=0.24.1,<0.25.0a0  but there are no viable options

etc.

[krassowski]

So it's working, but:

• I had to comment out additional xeus-cling packages
• the workspace restoration does not work (it did not work prior to this PR either)

I kept most packages unpinned for now, but we will probably want to pin them with a working resolution once we are happy with the setup.

[andrii-i]

"Interactive Widgets" section of demo/notebooks/Cpp.ipynb relies on xeus stack so we might want to temporary remove that part of the demo notebook. Everything else works great (tested demo folder), thank you for working on this @krassowski.

[andrii-i]

Binder is not caching the image (probably due to limited capacity) and has to build it every time with ~75% failure rate for me. Is it the same on your end?

[manics]

I wouldn't rely on binder at the moment, as we're still having problems due to a reduction in capacity and some configuration issues with the other hosts. If it mostly works with mybinder, or at least with repo2docker, that's probably good enough.

[fcollonval]

• the workspace restoration does not work (it did not work prior to this PR either)

I fixed this on master and rebase to fix it here too.

[fcollonval]

6a314c6e66b77a633fd0412157aaa8ccb9c769f1 works

Now I still need to figure out why the installation of the r-packages crashes.

[fcollonval]

I'm merging as is as it is working and will open a follow-up to fix installing the R kernel

[andrii-i]

@fcollonval, @krassowski thank you for working on this