How to demonstrate memory visibility problems in Go?

I'm giving a presentation about the Go Memory Model. The memory model says that without a happens-before relationship between a write in one goroutine, and a read in another goroutine, there is no guarantee that the reader will observe the change.

To have a bigger impact on the audience, instead of just telling them that bad things can happen if you don't synchronize, I'd like to show them.

When I run the below code on my machine (2017 MacBook Pro with 3.5GHz dual-core Intel Core i7), it exits successfully.

Is there anything I can do to demonstrate the memory visibility issues?

For example are there any specific changes to the following values I could make to demonstrate the issue:

• use different compiler settings
• use an older version of Go
• run on a different operating system
• run on different hardware (such as ARM or a machine with multiple NUMA nodes).

For example in Java the flags -server and -client affect the optimizations the JVM takes and lead to visibility issues occurring.

I'm aware that the answer may be no, and that the spec may have been written to give future maintainers more flexibility with optimization. I'm aware I can make the code never exit by setting GOMAXPROCS=1 but that doesn't demonstrate visibility issues.

package main
var a string
var done bool

func setup() {
    a = "hello, world"
    done = true
}

func main() {
    go setup()
    for !done {
    }
    print(a)
}