Get yourself some thin cyanoacrylate & cyanoacrylate activator, mask off anything that you don’t want to stick, then open up the crack scissor fashion & using a cotton bud laced with the activator, clean both surfaces, if you can get to root of the crack drill a very small hole (1mm is ideal) allow the crack to come back together & open the top of the crack ever so slightly, (use your 1mm drill to hold it open) drip some cyanoacrylate down & allow capillary action to draw it down to the root. Once the drill hole is filled hold the crack closed, but not too tight that you expel the glue, squirt the job with activator, it should cure almost instantly. Make a cup of tea & wonder at the new skill you have just learned.