So I'm still having trouble debugging this issue in the jupyter-book plugin where the kernel is dying. There are a few other sorts of errors, but I think they all have to do with how pex is running the script. I've now tried setting up a venv and successfully run jupyter book. Then I pip freeze the requirements and build a pex file with the -c flag. When I run jupyter-book from that pex file it fails. So it can't be a requirements issue since the requirements would be identical. Looking for any ideas on how to debug this. Another option is to push the plug-in as is and try to figure out the notebook execution in the future.