Analyze checkbox callback #19

[fcollonval]

This modify the example to (hopefully) demonstrate the problem on Binder.

[fcollonval]

@martinRenou I wrote a minimal notebook that is failing locally for me (i.e. the checkboxes are not triggering the callbacks). And it is not working on binder neither.

The server trace for the FailingNotebook when run locally:

[Voila] Using /tmp to store connection files
[Voila] Storing connection files in /tmp/voila_ct2aj6yb.
[Voila] Serving static files from /home/fcollonval/miniconda3/envs/voila/lib/python3.8/site-packages/voila/static.
[Voila] Voila is running at:
http://localhost:8866/
[Voila] Kernel started: 53caf19e-5e03-4ee2-b1ef-7b05522daa3d
CONDA_PREFIX=/home/fcollonval/miniconda3/envs/voila
WARNING:tornado.general:404 DELETE /api/kernels/ea901eeb-17f8-42aa-98c3-5fe2791f0ae5?1599490962042 (127.0.0.1): Kernel does not exist: ea901eeb-17f8-42aa-98c3-5fe2791f0ae5
[Voila] WARNING | Kernel does not exist: ea901eeb-17f8-42aa-98c3-5fe2791f0ae5
WARNING:tornado.access:404 DELETE /api/kernels/ea901eeb-17f8-42aa-98c3-5fe2791f0ae5?1599490962042 (127.0.0.1) 0.77ms
[IPKernelApp] WARNING | No such comm: fc81f2377d0d44fc83be5401c6e23606
[IPKernelApp] WARNING | No such comm: 2ec25363363541acbc7c56df44e8b142
[IPKernelApp] WARNING | No such comm: ebab06b9986b4dfe8ed1ba37f2c699a7
[IPKernelApp] WARNING | No such comm: f99474b1b1314039b83b7695e4520b6d
[IPKernelApp] WARNING | No such comm: 9db17770684b4b8b827d91d05a6688b4
[IPKernelApp] WARNING | No such comm: b9fd0ae0cfa84355a20e573a8bfb1102
[IPKernelApp] WARNING | No such comm: ebab06b9986b4dfe8ed1ba37f2c699a7
[IPKernelApp] WARNING | No such comm: ebab06b9986b4dfe8ed1ba37f2c699a7
[IPKernelApp] WARNING | No such comm: ebab06b9986b4dfe8ed1ba37f2c699a7
[IPKernelApp] WARNING | No such comm: ebab06b9986b4dfe8ed1ba37f2c699a7
[IPKernelApp] WARNING | No such comm: ebab06b9986b4dfe8ed1ba37f2c699a7

With the default template

[Voila] Storing connection files in /tmp/voila_nmo0d7v6.
[Voila] Serving static files from /home/fcollonval/miniconda3/envs/voila/lib/python3.8/site-packages/voila/static.
[Voila] Voila is running at:
http://localhost:8866/
WARNING:tornado.general:404 GET /api/kernels/53caf19e-5e03-4ee2-b1ef-7b05522daa3d/channels?session_id=4b27e52d-9262-471a-a7ef-7623742033ba (::1): Kernel does not exist: 53caf19e-5e03-4ee2-b1ef-7b05522daa3d
WARNING:tornado.access:404 GET /api/kernels/53caf19e-5e03-4ee2-b1ef-7b05522daa3d/channels?session_id=4b27e52d-9262-471a-a7ef-7623742033ba (::1) 37.62ms
WARNING:tornado.general:404 GET /api/kernels/53caf19e-5e03-4ee2-b1ef-7b05522daa3d/channels?session_id=c754380e-fe9c-4622-997d-2ab8f1b252f1 (::1): Kernel does not exist: 53caf19e-5e03-4ee2-b1ef-7b05522daa3d
WARNING:tornado.access:404 GET /api/kernels/53caf19e-5e03-4ee2-b1ef-7b05522daa3d/channels?session_id=c754380e-fe9c-4622-997d-2ab8f1b252f1 (::1) 1.28ms
[Voila] Kernel started: 8d581682-415d-4f7f-b74e-216d140c8b92
CONDA_PREFIX=/home/fcollonval/miniconda3/envs/voila
WARNING:tornado.general:404 GET /api/kernels/53caf19e-5e03-4ee2-b1ef-7b05522daa3d/channels?session_id=febd19cd-53b6-4336-a32e-1d4fbd36a691 (::1): Kernel does not exist: 53caf19e-5e03-4ee2-b1ef-7b05522daa3d
WARNING:tornado.access:404 GET /api/kernels/53caf19e-5e03-4ee2-b1ef-7b05522daa3d/channels?session_id=febd19cd-53b6-4336-a32e-1d4fbd36a691 (::1) 1.31ms
[Voila] WARNING | Replacing stale connection: 53caf19e-5e03-4ee2-b1ef-7b05522daa3d:4b27e52d-9262-471a-a7ef-7623742033ba

I'm intrigued by the Replacing stale connection. Do you have any idea where it comes from?