People can find themselves suddenly without a roof over their heads because of eg war or some natural disaster. Maybe the following automated building tool would help.
A small, autonomous robotic truck would be capable of moving only in circular arcs (of fixed length). Placed on a field, it moves backwards, along a circular arc and scoops up some earth. It then moves forwards and, injecting small quantities of water, it exudes a stream of mud paste along the arc. This backwards and forwards motion continues forming a spiral which overlaps itself (with gradual decrease in arc radius) until a hemispherical ‘igloo’ has been constructed -a little like a wasp’s nest).
For people who may be too weak to build their own shelter, this ultra-simple machine would be able to deliver a large number of rudimentary dwellings, working 24 hours per day.
If you required some extra headroom, the truck could, at some point, cut through the wall of the hut and excavate earth in circular arcs from the floor inside.
Since writing this, I have come across this recent development.