Setup:
Have a look at my configuration:
$ echo $GOPATH && ls -r $GOPATH /home/cyrus/.go src pkg bin $ echo $GOROOT &&
i had setup GOPATH and it showed correctly with command go env. i had to give the correct permissions to the go directory using chmod and install gb by go get github.com/constabulary/gb/....
GOPATH
go env
chmod
gb
go get github.com/constabulary/gb/...