Fix local server

dns/transport/local/local.go

@@ -85,6 +85,10 @@ func (t *Transport) exchangeParallel(ctx context.Context, systemConfig *dnsConfi
 	results := make(chan queryResult)
 	startRacer := func(ctx context.Context, fqdn string) {
 		response, err := t.tryOneName(ctx, systemConfig, fqdn, message)
+		addresses, _ := dns.MessageToAddresses(response)
+		if len(addresses) == 0 {
+			err = E.New(fqdn, ": empty result")
+		}
 		select {
 		case results <- queryResult{response, err}:
 		case <-returned:
@@ -92,14 +96,25 @@ func (t *Transport) exchangeParallel(ctx context.Context, systemConfig *dnsConfi
 	}
 	queryCtx, queryCancel := context.WithCancel(ctx)
 	defer queryCancel()
+	var nameCount int
 	for _, fqdn := range systemConfig.nameList(domain) {
+		nameCount++
 		go startRacer(queryCtx, fqdn)
 	}
-	select {
-	case <-ctx.Done():
-		return nil, ctx.Err()
-	case result := <-results:
-		return result.response, result.err
+	var errors []error
+	for {
+		select {
+		case <-ctx.Done():
+			return nil, ctx.Err()
+		case result := <-results:
+			if result.err == nil {
+				return result.response, nil
+			}
+			errors = append(errors, result.err)
+			if len(errors) == nameCount {
+				return nil, E.Errors(errors...)
+			}
+		}
 	}
 }
 
@@ -120,7 +135,7 @@ func (t *Transport) tryOneName(ctx context.Context, config *dnsConfig, fqdn stri
 			return response, nil
 		}
 	}
-	return nil, lastErr
+	return nil, E.Cause(lastErr, fqdn)
 }
 
 func (t *Transport) exchangeOne(ctx context.Context, server M.Socksaddr, question mDNS.Question, timeout time.Duration, useTCP, ad bool) (*mDNS.Msg, error) {