In my 2-3 years of Scrum implementation, this is the first time wherein our team didn't deliver an increment by the end of the sprint. I can name a number of reasons why we ended up like this but the one that I really blame is myself for I am the Scrum master.
Anyhow, have you encountered this scenario as well?
In the Scrum guide, I don't see any indication that you can't present undone work (untested), is my understanding correct?
What else do you think we should do in the sprint review?