I keep track of my version of Spigot, currently 1.9.4, and i use momentarilly Buildtools for windows, tried 'latest version' aswell the 1.9.4 version to update the spigot.jar.
At this moment, i still get 1 version behind, and i tried both options, but 'latest' is in buildtools's opinion 1.9.2 whilst it is currently at 1.9.4.
So i hope i gave the right info, because now i have the feeling i am behind updating...