Hello,
I found out today that winit no longer builds on OpenBSD, since it uses an older version of wayland-client (v0.21) and an older version of smithay-client-toolkit (v0.4.3) that both depend on an older nix crate (v0.12) that does not compile on OpenBSD. Bumping wayland-client to v0.23.1 and smithay-client-toolkit to v0.6.0 fixes this issue for me.
Thanks,
Rob