I cannot reproduce on my machine either. Are you using anything like an antivirus software, or some kind of crash handler?

I don't think it is the runtime that causes it to hang, so it probably cannot detect and emit an error either.

I cannot reproduce on my machine either. Are you using anything like an antivirus software, or some kind of crash handler?

Yes. I also suspect that it's the pre-installed security software that causes this. I managed to disable it today and the problem did go away.

I don't think it is the runtime that causes it to hang, so it probably cannot detect and emit an error either.

Sure, but I wonder what action the runtime trying to do that has been blocked? If it's something like memory access or syscall, shouldn't the action return an error or maybe timeout?

I also tried getting the goroutine profile in a seperate go routine to figure out what's going on.:

package main

import (
	"log"
	"runtime"
	"time"
)

func main() {
	go func() {
		time.Sleep(time.Second)
		records := make([]runtime.StackRecord, runtime.NumGoroutine())
		log.Println("running GoroutineProfile")
		log.Println(runtime.GoroutineProfile(records))
		log.Println("GoroutineProfile:", records)
	}()

	var a *int
	*a += 1
	log.Println(a)
}

I can see the log running GoroutineProfile printed as expected, but runtime.GoroutineProfile seems to be blocked at trying to stop the world.

BTW the software seems to cause the problem is Symantec Endpoint Protection. My colleagues with the same software enabled kindly helped me running the same program on their machines, but none can reproduce the problem :(

I used delve to debug the program and the program is blocked at this instruction:

The same problem can be reproduced with c.

#include <stdio.h>

int main() {
	int *a = NULL;
	int b = *a;
	return 0;
}

The only difference is that the c program can be stopped with <ctrl+c>, and sometimes it stopped after blocking for a few minutes without printing any error.

Looks like this is not language specific, and the runtime probably can't do anything about it, please feel free to close this issue if no further actions is needed.