example ¶ cat main.go 
// +build go1.10

package main

func main() {
	println("hello")
}
example ¶ go version
go version go1.9.2 darwin/amd64
example ¶ go build
can't load package: package .: build constraints exclude all Go files in /tmp/example

example ¶ cat main.go 
// +build go1.9

package main

func main() {
	println("hello")
}
example ¶ go version
go version go1.9.2 darwin/amd64
example ¶ go build ; echo $?
0
example ¶ GOROOT=/tmp/go /tmp/go/bin/go version
go version go1.8.5 darwin/amd64
example ¶ GOROOT=/tmp/go /tmp/go/bin/go build
can't load package: package .: no buildable Go source files in /tmp/example

// +build go1.10

package main

import (
	"fmt"
)

func main() {
	fmt.Println("Hello, playground")
}

go version
go version go1.6.2 linux/amd64

go build x.go
./x
Hello, playground