Surface the Pyodide logs to the UI

[jtpio]

For jupyterlite/jupyterlite#1498.

Depends on jupyterlite/jupyterlite#1642.

• Report cricital logs if an exception is caught during the kernel initialization process
• Expose a new (optional) logger function to report kernel logs

jupyterlite-kernel-status-indicator.mp4

jupyterlite-kernel-critical.mp4

[github-actions]

👈 Try it on ReadTheDocs

[jtpio]

cc @agriyakhetarpal

Wondering if there is a better way to do this? The idea would to get everything that usually gets logged by Pyodide in the dev tools console, at startup but also when loading new packages dynamically.

[hoodmane]

You probably want to do this and also to set custom standard steam handles. But I assume you're already setting the stream handlers somewhere.

[juntyr]

So there are two parts here. One is logging during package loading and one is logging messages sent to Pyodide's but not Python's stdout/stderr. The latter you can override using _pyodide.setStdout and _pyodide.setStderr. The former is a bit trickier. Overriding loadPackage works but only if it hasn't already been imported using from pyodide_js import loadPackage anywhere yet. Also, overriding it to always provide the custom callbacks means that users can no longer override it themselves. I still think that in the long term adding something like pyodide/pyodide#5442 to Pyodide to override the default stream for package logging would be better

[hoodmane]

I think this override does respect it if the user manually calls loadPyodide with their own callbacks.

[hoodmane]

@ryanking13 maybe we should consider merging some version of pyodide/pyodide#5442 as a stop-gap solution until a more general thing exists. Is anyone planning to work on this soon?

[juntyr]

I'm excited to use this feature!

[jtpio]

These logs are reported as info, which will not make the log console status bar item flash by default since it defaults to warning.

Some users have reported the flash to be irritating: jupyterlab/jupyterlab#11225. So we can let users choose their log level and not default to info.

[agriyakhetarpal]

Ah, sorry, @jtpio, I didn't see that I was pinged here!

I remember that @juntyr's https://github.comclimet-eu/pyodide was doing this sort of thing by calling a bunch of pyodide.code.run_js to write to the output streams, and while it was a hack, it seemed to work well.

Edit: oh, I just went through the linked issue, and I see that Juniper has already linked it in their response in jupyterlite/jupyterlite#1498 (comment) 😄

I think the origLoadPackage approach should be fine for now, as I don't think we have a JS API that writes to Pyodide's stdout/stderr.

That said, I'm not an expert on the JS side for Pyodide, so perhaps Hood and Gyeongjae would know :) cc: @hoodmane @ryanking13