Environment configuration:

RyanMacbookPro:work$ env | grep GO

GOBIN=/usr/local/go/bin

GOARCH=amd64

GOROOT=/usr/local/go

GOOS=darwin

GOPATH=/Users/ryan/go

Perform installation

sudo go get github.com/nsf/gocode

prompt:

cannot download, $GOPATH not set. For more details see: go help gopath

solution:

sudo env GOPATH=/Users/ryan/go go get github.com/nsf/gocode