Go Dump Goroutines on Exit

dump.go

package main

import (
	"fmt"
	"os"
	"os/signal"
	"runtime"
	"syscall"
	"time"
)

func main() {
	sig := make(chan os.Signal, 1)
	signal.Notify(sig, syscall.SIGINT, syscall.SIGQUIT)
	cancel := make(chan bool)
	go func() {
		fmt.Print("running")
		for {
			<-time.After(time.Second)
			fmt.Print(".")
		}
	}()
	go func() {
		<-sig
		fmt.Printf("\nstopping...\n")
		buf := make([]byte, 1<<20)
		n := runtime.Stack(buf, true)
		fmt.Printf("\n*** goroutine dump\n%s\n*** end\n", buf[:n])
		cancel <- true
	}()
	<-cancel
	fmt.Println("done")
}

The output of this prints something like:

% go run main.go
running..^C
stopping...

*** goroutine dump...
goroutine 8 [running]:
main.main.func2()
        /Users/paul/Downloads/main.go:27 +0x7c
created by main.main in goroutine 1
        /Users/paul/Downloads/main.go:23 +0xd3

goroutine 1 [chan receive]:
main.main()
        /Users/paul/Downloads/main.go:31 +0xdf

goroutine 17 [syscall]:
os/signal.signal_recv()
        /usr/local/Cellar/go/1.24.3/libexec/src/runtime/sigqueue.go:149 +0x25
os/signal.loop()
        /usr/local/Cellar/go/1.24.3/libexec/src/os/signal/signal_unix.go:23 +0x13
created by os/signal.Notify.func1.1 in goroutine 1
        /usr/local/Cellar/go/1.24.3/libexec/src/os/signal/signal.go:152 +0x1f

goroutine 7 [chan receive]:
main.main.func1()
        /Users/paul/Downloads/main.go:19 +0x5e
created by main.main in goroutine 1
        /Users/paul/Downloads/main.go:16 +0x85

*** end
done