Where is the Protocol-hack jar?( Build 1646 )

http://ci.md-5.net/view/SpigotMC/job/Spigot/

old builds

 

Use ViaVersion plugin instead of a 1.8/1.9 protocol hack.

 

there is no way to get that build. Downloading that build of spigot or any other build is illegal. Buildtools is the only way to get spigot.

 

downloading of spigot old spigot builds is illegal due to a dmca takedown (google about that or search the drama forum)
downloading of new spigot builds is illegal because they would package code by mojang which hurts thier and spigots licence.

 

You can still legally download the source from Stash and compile it yourself.

 

which is basicly what buildtools does. You need to clone it, apply the patches and compile it. I did not mention that because it is not realy an option for most ppl (it requires git, maven, a jdk, a ide, a shell)