What causes "output file must be specified" in hyperledger/fabric?

Pass exactly one positional arg: peer lifecycle chaincode package ./basic_1.0.tar.gz --path ... --lang ... --label ...

output file must be specified

Error message

output file must be specified

What it means

PackageInput.Validate returns this when no output file argument was provided to the package command. The output file is the .tar.gz chaincode package path that the command writes; without it there is nothing to write to.

Source

Thrown at internal/peer/lifecycle/chaincode/package.go:57

// 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]",
		Short:     "Package a chaincode",
		Long:      "Package a chaincode and write the package to a file.",
		ValidArgs: []string{"1"},

View on GitHub (pinned to 2736b63f8f)

Solutions

Pass exactly one positional arg: peer lifecycle chaincode package ./basic_1.0.tar.gz --path ... --lang ... --label ...
If constructing PackageInput programmatically, set OutputFile to a writable path before calling Validate/Package.
Check the path is writable by the invoking user to avoid the follow-up write failure (error writing chaincode package to %s).

Example fix

// before
p := &PackageInput{Path: path, Type: "go", Label: label}
// after
p := &PackageInput{Path: path, Type: "go", Label: label, OutputFile: "./mycc_1.0.tar.gz"}
if err := p.Validate(); err != nil {
    return err
}

Defensive patterns

Strategy: validation

Validate before calling

#!/bin/bash
OUT="${1:-}"
[ -n "$OUT" ] || { echo "usage: package <output-file.tar.gz>"; exit 1; }
peer lifecycle chaincode package "$OUT" --path "$CC_SRC_PATH" --lang "$CC_LANG" --label "$LABEL"

Try / catch

if ! out=$(peer lifecycle chaincode package "$OUT" ... 2>&1); then
  case "$out" in
    *"output file must be specified"*) echo "Pass exactly one positional arg: <output .tar.gz path>"; exit 2 ;;
    *) echo "$out"; exit 1 ;;
  esac
fi

Prevention

Always supply exactly one positional output filename.
Choose an output path inside a pre-created, writable directory.
If calling PackageInput programmatically, set OutputFile before Validate.
Verify writability with touch "$(dirname "$OUT")/.wtest" first.

When it happens

Trigger: Running `peer lifecycle chaincode package` with zero positional args (caught earlier by PackageChaincode's arg count check) or with --output-file style input left empty when setInput was bypassed, e.g. programmatic use of the PackageInput struct.

Common situations: Programmatic callers constructing PackageInput directly without OutputFile; wrapped CLI tools that forward args incorrectly; templates where the output filename variable was empty.

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/e4dcd75f7f815d1e. Report an issue: GitHub.