Stonewall and giveaway are incompatible, or there is a bug

When I attempt to create a custom variant with stonewall and giveaway, the pieces don't turn into walls. maybe I misunderstand what stonewall is. Can someone explain it to me?

You need fatal capture for stonewall to work

Stonewall makes it so that dead pieces cannot be captured, but does not make any pieces become dead. to make capturing pieces die, enable fatal capture.

this is more useful in four player games if you dont put fatal capture, since StoneWall only would work for decorative purposes in 2 player variants.