>>11754186>since Mars doesn't have a magnetic fieldYou could put magnet as a shield at L1. It's relatively feasible with today's technology.
Problem is that there still isn't enough GHGs and water on the planet to make it habitable. You would need to get your atmosphere from elsewhere.
At that point, Venus might be better candidate for terraforming - you need solar shading to cool it down quite a bit and lots of hydrogen to reduce atmosphere to inert elemental sulfur and water.
it's a pretty good building material given the conditions
https://en.wikipedia.org/wiki/Sulfur_concreteBut if you have infrastructure to haul gigatons of hydrogen and carbohydrates from outer giants to rocky planets, you might as well build orbital habitats from asteroids and you could live there within decades and not thousands of years for what would be considered caveman dwelling at the bottom of a gravity well.
