It is likely the OP is running Emacs from the packaged keg version from Homebrew (Homebrew has 2 emacs recipes, one which downloads the soruces and builds and one which downloads the pre-built binary from the emacs for mac osx site). My suggestion would be to remove the installed Emacs and then install the base recipe version that downloads the sources and builds in /usr/local tree. Once they have worked things out and know how to get things working to access the remote site, they can switch back to the pre-built version if they prefer.
However, putting all that aside, I'm not sure the OP needs to go through all of this anyway. For what they are doing, the version of tramp which is included in Emacs should be fine to verify they can do what they want. It isn't clear what changes they are trying to make or why they need separate sources from savannah. Unless the OP is implementing a whole new protocol for ftrampj, they probably only need to adjust some of the tramp config variables.