order, conf := systemConf().hostLookupOrder(r, host)
	if order == hostLookupCgo {
		return cgoLookupIP(ctx, network, host)
	}
	ips, _, err := r.goLookupIPCNAMEOrder(ctx, network, host, order, conf)
	return ips, err
}

func (r *Resolver) lookupPort(ctx context.Context, network, service string) (int, error) {
	// Port lookup is not a DNS operation.

func (r *Resolver) goLookupIP(ctx context.Context, network, host string, order hostLookupOrder, conf *dnsConfig) (addrs []IPAddr, err error) {
	addrs, _, err = r.goLookupIPCNAMEOrder(ctx, network, host, order, conf)
	return
}

func (r *Resolver) goLookupIPCNAMEOrder(ctx context.Context, network, name string, order hostLookupOrder, conf *dnsConfig) (addrs []IPAddr, cname dnsmessage.Name, err error) {

		_, _, err := r.goLookupIPCNAMEOrder(context.Background(), "ip", "notarealhost", order, nil)
		if err == nil {
			t.Errorf("%s: expected error while looking up name not in hosts file", name)
			continue
		}

		// Now check that we get an address when the name appears in the hosts file.