node: fix listening on IPv6 address (#27628) (#27635)

internal/debug/flags.go

@@ -19,6 +19,7 @@ package debug
 import (
 	"fmt"
 	"io"
+	"net"
 	"net/http"
 	_ "net/http/pprof"
 	"os"
@@ -308,7 +309,7 @@ func Setup(ctx *cli.Context) error {
 
 		port := ctx.Int(pprofPortFlag.Name)
 
-		address := fmt.Sprintf("%s:%d", listenHost, port)
+		address := net.JoinHostPort(listenHost, fmt.Sprintf("%d", port))
 		// This context value ("metrics.addr") represents the utils.MetricsHTTPFlag.Name.
 		// It cannot be imported because it will cause a cyclical dependency.
 		StartPProf(address, !ctx.IsSet("metrics.addr"))