gotip, but using $GOPATH
The "gotip" tool is great for using the current HEAD of the go development branch, but it does not specify where to install to. It just installs to "$HOME/sdk/gotip" without allowing any kind of configuration.
All this tool does is copy the existing gotip code but uses "$GOPATH" if it is set, which will then install there instead, which is typically "$HOME/go/sdk/gotip".
Other than this minor change, there have been no amendments made. If this tool ever breaks, I will likely re-copy the code from the latest version of gotip and make the same changes.
Good luck, have fun!