'AsyncIOLoopKernelManager' object has no attribute 'ports_changed'

[fcollonval]

Description

#1047 introduces a new assumption on the KernelManager API that is not correct kernel_manager.ports_changed is not mandatory (it does not exist on the abstract class nor on the default jupyter_client.ioloop.AsyncIOLoopKernelManager) :

jupyter_server/jupyter_server/services/kernels/connection/channels.py

Line 336 in cd060da

if self.kernel_manager.ports_changed(self.kernel_id):

Reproduce

Error seen on JupyterLab CI: https://github.com/jupyterlab/jupyterlab/actions/runs/3530210941/jobs/5921960684

Expected behavior

No error

Reference

Version: jupyter_server-2.0.0rc6

[fcollonval]

The call existed in the code prior to #1047 in jupyter_server/services/kernels/handlers.py#L464

[Zsailer]

Thanks, @fcollonval. Looks like #1047 calls ports_changed at the wrong level.

This has been an annoying readability issue in Jupyter Server for a long time. When JS says kernel_manager is usually means the Mapping/Multi Kernel Manager, not the individual Kernel Managers. in #1047, I tried to be more explicit, but looks like I got it wrong in this instance.

[fcollonval]

Thanks @Zsailer for the quick fix and thanks @blink1073 for the new release

Happy Thanksgiving to both of you