[yt-users] Stuck on installing Forthon

Hi all, I am following the introductions to setup Parallel HOP but I got stuck at "cd into yt/utilities/kdtree". I dont have a folder name "kdtree" in yt/utilities. Is it because I installed the yt in a wrong way? I installed the yt using "All-in-One Installation Script", and when I was installing it, everything went smoothly. But I knew that before I installed yt, there is a python already on my Mac. Any tips? Thanks a lot! Lei