Next, I took my "portable" Wayland patchset and rebased it onto latest upstream main. It's both better and worse; the upstream have done some BSD portability work, so equivalents of some of my changes have effectively been upstreamed, but also they added eventfd usage, so, yay, more things to patch out.
Anyway, so I got Wayland building on the Hurd once again. The tests don't yet pass, I'll need to look into that tomorrow.
After that: Owl, and gtk with its Wayland backend.