hyperledger/fabric · error

nil data bytes

Error message

nil data bytes

What it means

PutChaincodeToFS persists both the parsed data and its serialized byte form (datab). This error fires when datab — the raw serialized bytes corresponding to the package — is nil while data is non-nil. The serialized bytes are what get written to disk, so the library refuses to continue without them.

Source

Thrown at core/common/ccprovider/sigcdspackage.go:302

	if ccpack.id == nil {
		return errors.New("id cannot be nil if buf is not nil")
	}

	if ccpack.sDepSpec == nil || ccpack.depSpec == nil {
		return errors.New("depspec cannot be nil if buf is not nil")
	}

	if ccpack.env == nil {
		return errors.New("env cannot be nil if buf and depspec are not nil")
	}

	if ccpack.data == nil {
		return errors.New("nil data")
	}

	if ccpack.datab == nil {
		return errors.New("nil data bytes")
	}

	ccname := ccpack.depSpec.ChaincodeSpec.ChaincodeId.Name
	ccversion := ccpack.depSpec.ChaincodeSpec.ChaincodeId.Version

	// return error if chaincode exists
	path := fmt.Sprintf("%s/%s.%s", chaincodeInstallPath, ccname, ccversion)
	if _, err := os.Stat(path); err == nil {
		return fmt.Errorf("chaincode %s exists", path)
	}

	if err := os.WriteFile(path, ccpack.buf, 0o644); err != nil {
		return err
	}

	return nil
}

View on GitHub (pinned to 2736b63f8f)

Solutions

1. Serialize the package into ccpack.datab (e.g., proto.Marshal of the CDSPackage) before calling PutChaincodeToFS
2. Use the standard packaging flow (peer install / processSignedCDS) so datab is set automatically
3. Regenerate the chaincode package from source and reinstall

Example fix

// before
pack.data = parsed
pack.datab = nil
ccprovider.PutChaincodeToFS(pack) // errors: nil data bytes

// after
pack.data = parsed
datab, err := proto.Marshal(pack)
if err != nil { return err }
pack.datab = datab
ccprovider.PutChaincodeToFS(pack)

if pack != nil && pack.Data != nil && pack.Datab == nil {
  return errors.New("package datab not serialized; marshal package first")
}

func hasSerializedBytes(p *ccprovider.SignedCDSPackage) bool {
  return p != nil && p.Datab != nil && len(p.Datab) > 0
}

err := ccprovider.PutChaincodeToFS(pack)
if err != nil {
  if strings.Contains(err.Error(), "nil data bytes") {
    datab, merr := proto.Marshal(pack)
    if merr != nil { return merr }
    pack.Datab = datab
    return ccprovider.PutChaincodeToFS(pack)
  }
  return err
}

When it happens

Trigger: A SignedCDSPackage built with the in-memory payload (data) but no serialized bytes (datab) — typically a package constructed in code or produced by a decoder path that skips the byte serialization step in processSignedCDS.

Common situations: Custom chaincode packaging tools, partial decoding of install packages after a Fabric upgrade, or tests that assemble package structs by hand.

Related errors

• env cannot be nil if buf and depspec are not nil
• nil data
• error writing chaincode install package to %s
• chaincode %s exists
• received nil proposal response

AI-assisted analysis of hyperledger/fabric@2736b63f8f (2026-09-04). Data as JSON: /api/errors/2341c3cbf0987db2. Report an issue: GitHub.