Trapping them in a building never worked for me. Even when not aggro i could not feed it. If taming in the desert use a flying combat mount. Use bug spray on the mount and yourself so you can land,dismount,feed and fly off clearing nearby dinos until next feed. This stops it aggroing on your mount and helps you avoid chasing it around on foot losing food/water
Please don’t listen to the boy who said with bug repellant, ghille and cactus broth that the aggro range is “literally zero” cause it’s not.. you can get super duper close without aggravating it but you can’t get too close so still be careful and try not to stand so close you can touch it or it will STILL AGGRO.