How to debug dead IJulia kernels (julia 1.4.1)

Alexander-Barth · May 8, 2020, 7:14am

I am trying to help two students whom I asked to install julia 1.4.1 and IJulia (one on Windows, and one on Kubuntu 20.04). Both have the issue that the IJulia kernel is crashing directly.

Here is a thread of the discussion:
https://github.com/Alexander-Barth/HF-radar-assim-exercise/issues/1

I have asked them to enable IJULIA_DEBUG:

ENV["IJULIA_DEBUG"]=true
using Pkg
Pkg.build("IJulia",verbose=true)

But so far we were not able to see any useful error message why the kernel is crashing.

Does somebody have an idea how to debug these issues?

Alexander-Barth · May 8, 2020, 8:59am

I am wondering if IJulia.set_verbose works as mentioned in the docs:

github.com

JuliaLang/IJulia.jl/blob/master/src/IJulia.jl#L54


      
          # InteractiveUtils is not used inside IJulia, but loaded in src/kernel.jl
          # and this import makes it possible to load InteractiveUtils from the IJulia namespace
          import InteractiveUtils
          
          
const depfile = joinpath(dirname(@__FILE__), "..", "deps", "deps.jl")
          isfile(depfile) || error("IJulia not properly installed. Please run Pkg.build(\"IJulia\")")
          include(depfile) # generated by Pkg.build("IJulia")
          
          
#######################################################################
          # Debugging IJulia
          
          
# in the Jupyter front-end, enable verbose output via IJulia.set_verbose()
          verbose = IJULIA_DEBUG
          """
              set_verbose(v=true)
          
          
This function enables (or disables, for `set_verbose(false)`) verbose
          output from the IJulia kernel, when called within a running notebook.
          This consists of log messages printed to the terminal window where
          `jupyter` was launched, displaying information about every message sent
          or received by the kernel.   Used for debugging IJulia.

I do not see much information in the julia terminal after running notebook() after ensuring that verbose is true. Wouldn’t it be useful to echo all jupyter message in the Julia terminal if verbose/debug is true?

cet · October 22, 2020, 1:59pm

Following this : https://discourse.julialang.org/t/using-ijulia-with-existing-jupyter-installation-outwith-anaconda/38832/11?u=cet
Maybe…

CET.