Test program to test Go'a netdns=cgo resolver on macOS

main.go

package main

import (
	"fmt"
	"log"
	"net"
)

func main() {
	cnames, addrs, err := net.LookupSRV("_salty", "_tcp", "home.arpa")
	if err != nil {
		log.Fatal(err)
	}
	fmt.Printf("cnames: %s\n", cnames)
	fmt.Printf("addrs:  #%v\n", addrs)
}

Build with:

$ CGO_ENABLED=1 go build .

Run with:

$ GODEBUG=netdns=cgo+1 ./test-netdns
go package net: using cgo DNS resolver
2022/04/02 00:47:02 lookup __salty.__tcp.home.arpa on 10.0.0.10:53: no such host

Note this is using my Mac's DNS server in /etc/resolv.confand not the Resolver in/etc/resolver/home.arpa`:

$ cat /etc/resolver/home.arpa
nameserver 127.0.0.1
port 5300

Expected output (using dig):

$ dig @127.0.0.1 -p 5300 srv _salty._tcp.home.arpa +short
0 0 443 salty.home.arpa.