Failure Is a Part of Life
It seems that some teachers really worry about failing or repeating students. They debate. They ponder. They worry about how the student will feel about repeating. They turn it into this big mess of emotion and conflict. I just don't think it needs to be that way. A student has either succeeded in doing the work and comprehending what has been taught or they haven't. There are shades of gray in this and some students are borderline, but the decision needs to be made. So make it and don't sweat it. Failing or repeating a level sucks, and I don't think there is anyway to make it enjoyable for the student. So just tell them they're failing or repeating and move on. It's like pulling off a band-aid.