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.

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
• chaincode exists
• error writing chaincode install package to
• received nil proposal response

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

Appendix: 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
}

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