hyperledger/fabric · error

unexpected error while marshaling TxIDIndexValProto message

Error message

unexpected error while marshaling TxIDIndexValProto message

What it means

Thrown in blockindex.indexBlock when proto.Marshal fails on a TxIDIndexValProto message built for the transaction-ID index. Protobuf marshal of a generated, validly-populated message practically never fails, so this is treated as 'unexpected' and indicates an internal invariant break (nil message, invalid proto definition/registry mismatch).

Source

Thrown at common/ledger/blkstorage/blockindex.go:122

	if index.isAttributeIndexed(IndexableAttrBlockNum) {
		batch.Put(constructBlockNumKey(blkNum), flpBytes)
	}

	// Index3 Used to find a transaction by its transaction id
	if index.isAttributeIndexed(IndexableAttrTxID) {
		for i, txoffset := range txOffsets {
			txFlp := newFileLocationPointer(flp.fileSuffixNum, flp.offset, txoffset.loc)
			logger.Debugf("Adding txLoc [%s] for tx ID: [%s] to txid-index", txFlp, txoffset.txID)
			txFlpBytes := txFlp.marshal()

			indexVal := &TxIDIndexValue{
				BlkLocation:      flpBytes,
				TxLocation:       txFlpBytes,
				TxValidationCode: int32(txsfltr.Flag(i)),
			}
			indexValBytes, err := proto.Marshal(indexVal)
			if err != nil {
				return errors.Wrap(err, "unexpected error while marshaling TxIDIndexValProto message")
			}
			batch.Put(
				constructTxIDKey(txoffset.txID, blkNum, uint64(i)),
				indexValBytes,
			)
		}
	}

	// Index4 - Store BlockNumTranNum will be used to query history data
	if index.isAttributeIndexed(IndexableAttrBlockNumTranNum) {
		for i, txoffset := range txOffsets {
			txFlp := newFileLocationPointer(flp.fileSuffixNum, flp.offset, txoffset.loc)
			logger.Debugf("Adding txLoc [%s] for tx number:[%d] ID: [%s] to blockNumTranNum index", txFlp, i, txoffset.txID)
			txFlpBytes := txFlp.marshal()
			batch.Put(constructBlockNumTranNumKey(blkNum, uint64(i)), txFlpBytes)
		}
	}

View on GitHub (pinned to 2736b63f8f)

Solutions

1. Read the wrapped cause beneath this message for the actual marshal error and identify which message fails.
2. Rebuild with the pinned protobuf/gogo-protobuf versions from go.mod (go mod tidy / go mod download; clear module cache if suspect).
3. Regenerate the proto types (protoc-gen-gogo) with the same generator versions the project uses instead of hand-editing generated code.
4. If it reproduces on one specific block, capture the block and file an issue; the block may contain data that trips the indexer (e.g. nil tx payload paths).

Example fix

// before: mismatched generated code after upgrading protobuf runtime
// ERROR: unexpected error while marshaling TxIDIndexValProto message
// after:
go mod tidy
go build ./...  // ensure pb.go regenerated with project's protoc-gen-gogo version

// Go: smoke-test marshal of the index value type before processing production blocks
func marshalOK(v *proto.TxIDIndexValProto) error {
	if v == nil {
		return errors.New("nil index value")
	}
	_, err := proto.Marshal(v)
	return err
}

// Go: log the wrapped cause with block/tx identifiers before failing the batch
if err := indexBlock(block); err != nil {
	if strings.Contains(err.Error(), "marshaling TxIDIndexValProto") {
		logger.Errorf("index marshal failed for block %d: %+v", block.Header.Number, errors.Cause(err))
	}
	return err
}

When it happens

Trigger: indexBlock (invoked from addBlock or syncIndex) while indexing transactions: only if the TxIDIndexValProto instance is nil or the proto message/registry is inconsistent (mismatched generated code vs runtime protobuf library, malformed proto descriptors).

Common situations: Custom builds where protoc-generated pb.go files were regenerated with an incompatible protoc/protobuf-go version; binary patches to the ledger package; corrupted Go module cache producing stale generated code.

Related errors

• error marshalling proto message to write to the snapshot fil
• error marshaling
• error marshaling computed config update
• error decoding the block number
• error decoding the data hash

AI-assisted analysis of hyperledger/fabric@2736b63f8f (2026-09-04). Data as JSON: /api/errors/1410293476b4f000. Report an issue: GitHub.