What causes "chaincode language must be specified" in hyperledger/fabric?

Add the flag: --lang golang (or java / node) to the package command.

chaincode language must be specified

Error message

chaincode language must be specified

What it means

PackageInput.Validate returns this when the --lang flag is empty. The language selects which platform packager (golang, java, node) builds the deployment payload and it is also written into metadata.json. Packaging cannot proceed without a known chaincode language.

Source

Thrown at internal/peer/lifecycle/chaincode/package.go:54

	Writer           Writer
}

// PackageInput holds the input parameters for packaging a
// ChaincodeInstallPackage
type PackageInput struct {
	OutputFile string
	Path       string
	Type       string
	Label      string
}

// Validate checks for the required inputs
func (p *PackageInput) Validate() error {
	if p.Path == "" {
		return errors.New("chaincode path must be specified")
	}
	if p.Type == "" {
		return errors.New("chaincode language must be specified")
	}
	if p.OutputFile == "" {
		return errors.New("output file must be specified")
	}
	if p.Label == "" {
		return errors.New("package label must be specified")
	}
	if err := persistence.ValidateLabel(p.Label); err != nil {
		return err
	}

	return nil
}

// PackageCmd returns the cobra command for packaging chaincode
func PackageCmd(p *Packager) *cobra.Command {
	chaincodePackageCmd := &cobra.Command{
		Use:       "package [outputfile]",

View on GitHub (pinned to 2736b63f8f)

Solutions

Add the flag: --lang golang (or java / node) to the package command.
Verify the shell variable (e.g. CC_RUNTIME_LANGUAGE) is exported and non-empty before the call.
Ensure the value matches a supported platform since validation only checks emptiness here but GetDeploymentPayload does strings.ToUpper(p.Input.Type) later.

Example fix

// before
args := []string{"-p", path, "--label", label} // lang missing
// after
args := []string{"--lang", "golang", "--path", path, "--label", label}

Defensive patterns

Strategy: validation

Validate before calling

#!/bin/bash
case "${CC_RUNTIME_LANGUAGE:-}" in
  golang|java|node) ;;
  *) echo "CC_RUNTIME_LANGUAGE must be golang, java, or node"; exit 1 ;;
esac
peer lifecycle chaincode package "$OUT" --path "$CC_SRC_PATH" --lang "$CC_RUNTIME_LANGUAGE" --label "$LABEL"

Try / catch

if ! out=$(peer lifecycle chaincode package "$OUT" --path "$P" --lang "$L" --label "$LABEL" 2>&1); then
  case "$out" in
    *"chaincode language must be specified"*) echo "Add --lang golang|java|node"; exit 2 ;;
    *) echo "$out"; exit 1 ;;
  esac
fi

Prevention

Always pass --lang (golang/java/node) with the package command.
Guard language variables with ${VAR:?} in CI scripts.
Use lowercase language names; the tool uppercases internally.
Pin the language in pipeline variables so it cannot go empty.

When it happens

Trigger: Running `peer lifecycle chaincode package` without --lang, or with an unset variable like $CC_RUNTIME_LANGUAGE that expands to empty.

Common situations: CI scripts where CC_RUNTIME_LANGUAGE was never set; docs examples using golang but the flag removed while editing; automation generating the CLI args programmatically and skipping the language field.

Understand the failure class

Background: "missing required argument" and "the following required arguments were not provided": what required-argument errors mean and how to fix them — this error's family across 20 libraries.

Related errors

AI-assisted analysis of hyperledger/fabric@2736b63f8f (2026-09-04). Data as JSON: /api/errors/fe7177c4ddd538a6. Report an issue: GitHub.