I got tired of manually setting my GOPATH when I went from one project to another,
so I wrote a small utility to set up my environment for me. It is similar in spirit to Python's
virtualenv, though it does less, and does it a little differently.
The main difference is that instead of an 'activate' script that sets up your environment, this opens up a new subshell for you to work in. It will also download and install the version of Go that you want it to.
NOTE: I do not have a Mac to test this on. I know it works on Linux, and I think it will work on OSX, but I'm not sure. If you want to test it, and maybe send me a pull request to fix any issues you find, I would appreciate it.
It is a single Python script, so you can just make it executable and put it somewhere in your path.
# you might need to add --no-check-certificate to the wget command...
$ wget -O ~/bin/goenv https://raw.github.com/pwoolcoc/goenv/master/goenv
# for the love of pete, don't just run scripts you get from the internet, check them first!
$ $EDITOR ~/bin/goenv
$ chmod +x ~/bin/goenv
$ cd /path/to/project
$ echo $GOPATH
# simplest usage
$ goenv
(golang-1.2) $ echo $GOPATH
/path/to/project:/path/to/project/pkg/somepkg
# specify Golang version
$ goenv --version 1.1
(golang-1.1) $