<s>[INST] package main

import (
	"fmt"
)

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

This is a "Hello, world!" program written in Go. But I want it to wait for some time before exiting after printing the message. 

To accomplish this, I've tried the following:

a. Add a `time.Sleep(1 * time.Second)` call. While this works, it blocks the main goroutine, which is undesirable since it's also responsible for running the event loop, and I don't want it to be blocked.

b. Add a `select {}` statement after the print statement. This also doesn't work since it blocks the goroutine.

I've tried using Go's concurrency features as well. Here's what I came up with:

```go
package main

import (
	"fmt"
	"time"
)

func main() {
	fmt.Println("Hello, world!")
	go func() {
		time.Sleep(1 * time.Second)
	}()
}
```

However, this still doesn't work since the main goroutine exits immediately, stopping the program, before the sleep goroutine is done.

How can I wait for the sleep goroutine to finish without blocking the main goroutine?[/INST]