In addition to these good recommendations, I swear by Beacon 527 multi-use glue.
It’s about the consistency of thick corn syrup, not too runny, soaks just enough into the gypsum, has a comfortable ‘working time’ so you can make adjustments after you stick the broken piece on, and since it dries with a flexible, silicone-like bond it’s basically shatter-proof. It’s my favorite!
It used to be called Bond 527 so it might be found under that name too. It is the same formula though.