This is what works for me, assuming an clean project created using 'zig init-exe':

At the top of your build.zig, import the raylib build.zig inside raylib's /src folder (exact path will depend where you've cloned raylib)

  const raySdk = @import("raylib/src/build.zig");

Use the imported addRaylib() function to build raylib, then link to the exe and add include path

  var raylib = raySdk.addRaylib(b, target, optimize, .{});
  exe.addIncludePath(.{ .path = "raylib/src" });
  exe.linkLibrary(raylib);

After that, you should be fine to just use @cImport to use raylib within your project

  const ray = @cImport({
    @cInclude("raylib.h");
  });

  pub fn main() void {
    ray.InitWindow(800, 450, "raylib [core] example - basic window");
    ...