No error message if channel cannot be deployed

Observed behavior

I seem to have exceeded my storage on an account where I try to programatically import content. However, no error message is given, that it is not possible to deploy the channel.

There are some hidden clues.

Expected behavior

Proper error messages should be shown.

Steps to reproduce the issue

1. Have a channels with exceeded storage space
2. Make an sushichef.py script and import

During the import process you will probably get some of the following error messages:

WARNING  WARNING: The following nodes have one or more descendants that could not be created:
WARNING         Danger signs in pregnancy (TopicNode): 5 descendants (b4fea06550267d0cecf434a2dd8002aa.mp4: local variable 'response' referenced before assignment)

These error messages will to my experience only show if storage space is exceeded.

You will still get the deploy link though:

https://studio.learningequality.org/channels/sometoken/staging

When going to that link, you will also have the possibility to deploy. You click deploy, but nothing is deployed. You can even go to the link again (which you are not able to, if the content is actually deployed).

Start by reproducing the issue with a sushichef.py import into a channel whose storage is exceeded, then inspect the warnings about descendants and the staging deploy link. Trace why deployment produces no visible error and verify that the user receives a proper error message when storage prevents deployment.