https://github.com/golang/go/wiki/Ubuntu ふむふむ
$ sudo apt install golang-1.8-go
$ go version
The program 'go' is currently not installed. You can install it by typing:
sudo apt install golang-go
あれれ?
$ /usr/lib/go-1.8/bin/go version
go version go1.8.1 linux/amd64
ふーむ
export GOPATH=$HOME/go
PATH=$PATH:/usr/lib/go-1.8/bin:$GOPATH/bin
でいっか。