more err log

server.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"crypto/tls"
 	"errors"
+	"fmt"
 	"io"
 	"log"
 	"net"
@@ -139,7 +140,7 @@ func (s *Server) dig(ctx context.Context, host string) (string, error) {
 	}
 	ip, err := s.resolver.LookupHost(ctx, search)
 	if err != nil {
-		return "", err
+		return "", fmt.Errorf("failed to dns lookup %s: %v", search, err)
 	}
 	if len(ip) == 0 {
 		return "", errors.New("name does not resolve")