Golang net.LookupIP not working when compiled with GOARCH=amd64? - go

Question

here is a simple program:
package main
import (
"fmt"
"net"
)
func main() {
nameserver, _ := net.LookupNS("mylab.local")
for _, ns := range nameserver {
addrs, errIP := net.LookupIP(ns.Host)
if errIP == nil {
fmt.Printf("%s\n",addrs[0].String())
} else {
fmt.Printf("%s\n", errIP.Error())
}
}
}
Here is the ouput compiled with GOARCH=amd64:
$ GOOS=linux GOARCH=amd64 go build -o test test.go
$ ./test
?
The output compiled with GOARCH=386:
$ GOOS=linux GOARCH=386 go build -o test test.go
$ ./test
192.168.56.3
I'm working on a "Ubuntu 18.04.6 LTS".
Is there something obvious I missed ?
Thank you
Update 1: I updated the code in order to print the errIP
The output compiled GOARCH=amd64:
$ GOOS=linux GOARCH=amd64 go build -o test test.go
$ ./test
lookup dc01.mylab.local.: no such host
$ ping -c1 dc01.mylab.local
PING dc01.mylab.local (192.168.56.3) 56(84) bytes of data.
64 bytes from dc01.mylab.local (192.168.56.3): icmp_seq=1 ttl=128 time=0.561 ms
Update 2: #hobbs
Here is the output with the environment var:
$ export GODEBUG=netdns=1
$ GOOS=linux GOARCH=amd64 go build -o test test.go
$./test
go package net: dynamic selection of DNS resolver
&{dc01.mylab.local.}
lookup dc01.mylab.local.: no such host
Update 3: Ok solved, thank you hobbs. I found that with arch 386, the resolver used was go. So after that I had a look at the documentation of the net package. I compiled as follow:
$ export GODEBUG=netdns=go
$ GOOS=linux GOARCH=amd64 go build -o test test.go
$ ./test
192.168.56.3