Hey,
Did you capture the Izila fort in the South of the map ? If so, Roshani should have been put in a cage in your village. Leave the village and return to it and Roshani should have a mission for you. Complete that mission and Roshani joins the Wenja tribe and you can build the hut.
PS: Roshani is a guy
Were you ever able to work this out? I can't see Roshani on the map either. I know where the Izila fort is located but I don't see the Roshani icon to begin the quest. I'm reluctant to capture the fort without seeing the Roshani icon there first because I don't want the game to be bugged. I've completed all the Tensay missions. Are there other missions to complete before the Roshani icon appears on the map?