kernel.requestExecute(content) error/exceptions logging

#1

Dear all,
I am working on an extension, which communicates with the kernel through requestExecute (https://jupyterlab.github.io/jupyterlab/services/classes/defaultkernel.html#requestexecute)

When the requested execution fails, I can’t seem to find the reason of the problem by any means. I checked all properties of the returned IFuture and don’t find any indication of the error message.

Will the kernel log its stderr and stdout somewhere on the file system? It is a python kernel.
I don’t know if the requested execution content has some syntax error which I don’t see or if an exception is thrown or some operating system function fails. The execution just breaks somewhere. It is very tedious if not impossible to debug.

Thank you
Ernst

#2

You can listen to messages by registering the onReply, etc. handler functions on the future, or listen to the future’s done promise and see the reply message there.