I was going to test
SAK-40018 on https://experimental.nightly.sakaiproject.org. I added a gb item and graded it, I added an assignment and had students submit (but it had not been graded at this point).
I had the students click on Gradebook and received a stacktrace. The instructor is able to view the gradebook.
Site with GB item and Assignment:
Site with no GB items created yet: