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Underground caves do exist on the Moon, radar observations confirm
(www.techspot.com)
This is a most excellent place for technology news and articles.
They've found hitting it with microwaves sinters it together pretty readily, so that would be the likely way they'd deal with it. Apparently also an effective way of making bricks out of it!
Niice https://www.sciencedirect.com/science/article/pii/S2352710224007617?via%3Dihub