For the shell we use the cmd2 module, whose version was not fixed in our setup.py dependencies list. Unfortunately, somewhere after cmd2 v0.9.12, breaking API changes have been introduced that went unnoticed by us but caused some features like custom commandline arguments to stop working properly. While we are investigating the impact of the changes, we are now shipping a hotfix release reverting to cmd2 v0.9.12 as our last known working version.