Make kernel exit properly when iopub port is already in use - #1594

Make kernel exit properly when iopub port is already in use#1594

JohanMabille merged 2 commits into

ipython:mainipython/ipykernel:mainfrom

krassowski:fix-port-race-recoverykrassowski/ipykernel:fix-port-race-recoveryCopy head branch name to clipboard