Backward compatibility for Go 1.16

[FrankFang]

Newbie here.
When I ran commands below:

$ go version
go version go1.16.8 linux/amd64
$ go mod init main
$ touch main.go
$ go get -u golang.design/x/clipboard                                                                                                                                     ✘ 1 
//go:build comment without // +build comment
$ go run main                                                                                                                                                             ✘ 1 
main.go:4:8: no required module provides package golang.design/x/clipboard; to add it:
        go get golang.design/x/clipboard
$ go get golang.design/x/clipboard                                                                                                                                        ✘ 1 
//go:build comment without // +build comment

I got //go:build comment without // +build comment, but the go.mod file never changed.
So how could I install golang-design/clipboard?

main.go

package main

import "fmt"
import "golang.design/x/clipboard"

func main(){
	fmt.Println("hi")
}

[FrankFang]

It works well for go 1.17.
Just upgrade go!

[changkun]

Yes, starting from 0.5, the package requires 1.17. If you can only use 1.16, then 0.4.6 can be an option for you.

[changkun]

Reopen for backward compatibility in Go 1.16. Also because of golang/go#48509.