Merge pull request #138 from walldiss/do-not-warn-known-headers

fix(verify): report known headers as soft failure

p2p/exchange.go

@@ -174,11 +174,14 @@ func (ex *Exchange[H]) Head(ctx context.Context, opts ...header.HeadOption[H]) (
 						headerRespCh <- headers[0]
 						return
 					}
-					log.Errorw("verifying head received from tracked peer", "tracked peer", from,
+					logF := log.Warnw
+					if errors.Is(err, header.ErrKnownHeader) {
+						logF = log.Debugw
+					}
+					logF("verifying head received from tracked peer", "tracked peer", from,
 						"height", headers[0].Height(), "err", err)
 					headerRespCh <- zero
 					return
-
 				}
 			}
 			// request ensures that the result slice will have at least one Header

sync/sync_head.go

@@ -172,7 +172,11 @@ func (s *Syncer[H]) verify(ctx context.Context, newHead H) (bool, error) {
 
 	var verErr *header.VerifyError
 	if errors.As(err, &verErr) && !verErr.SoftFailure {
-		log.Errorw("invalid network header",
+		logF := log.Warnw
+		if errors.Is(err, header.ErrKnownHeader) {
+			logF = log.Debugw
+		}
+		logF("invalid network header",
 			"height_of_invalid", newHead.Height(),
 			"hash_of_invalid", newHead.Hash(),
 			"height_of_subjective", sbjHead.Height(),