It is now possible to install/bootstrap Go 1.7rc5 with homebrew again on 10.12, using brew install go --devel. But all other formulas (syncthing, synching-inotify, godep) still require stable Go (of course) and fail.
If you are stupid and mistake this for braveness like me, you can switch the labels for “devel” and “stable” in the go.rb formula and things might just work…
(don’t do this unless you are desperate, you will have to restore this change after every brew update, although homebrew is nice enough to git stash it before update)
(if godep complains about not finding dependencies, try reinstalling godep)