hyperledger/fabric · error

Error Unmarshalling YAML: %s

Error message

Error Unmarshalling YAML: %s

What it means

getConfig parses the read YAML data into the Config struct with yaml.Unmarshal. If the content is not valid YAML or does not match the expected schema, this error wraps the YAML parse error. It is a configuration content problem, not an I/O problem.

Source

Thrown at cmd/cryptogen/main.go:274

			return nil, fmt.Errorf("Error reading configuration: %s", err)
		}

		configData = string(data)
	} else if *extConfigFile != nil {
		data, err := io.ReadAll(*extConfigFile)
		if err != nil {
			return nil, fmt.Errorf("Error reading configuration: %s", err)
		}

		configData = string(data)
	} else {
		configData = defaultConfig
	}

	config := &Config{}
	err := yaml.Unmarshal([]byte(configData), &config)
	if err != nil {
		return nil, fmt.Errorf("Error Unmarshalling YAML: %s", err)
	}

	return config, nil
}

func extend() {
	config, err := getConfig()
	if err != nil {
		fmt.Printf("Error reading config: %s", err)
		os.Exit(-1)
	}

	for _, orgSpec := range config.PeerOrgs {
		err = renderOrgSpec(&orgSpec, "peer")
		if err != nil {
			fmt.Printf("Error processing peer configuration: %s", err)
			os.Exit(-1)
		}

View on GitHub (pinned to 2736b63f8f)

Solutions

1. Read the wrapped YAML error line/column and fix that spot in the file.
2. Validate the YAML first (yamllint or a YAML parser) before running cryptogen.
3. Replace tabs with spaces and ensure consistent indentation.
4. Compare against a known-good crypto-config.yaml from the fabric-samples repo.

Example fix

// before (tabs break YAML)
PeerOrgs:
	- Name: Org1
// after
PeerOrgs:
  - Name: Org1

// validate YAML before invoking cryptogen
import "gopkg.in/yaml.v3"
var probe map[string]any
if err := yaml.Unmarshal([]byte(configData), &probe); err != nil {
    log.Fatalf("invalid YAML: %v", err)
}
if _, ok := probe["PeerOrgs"]; !ok { log.Fatal("missing PeerOrgs section") }

When it happens

Trigger: Running cryptogen generate/extend with a --config file containing malformed YAML (bad indentation, tabs, duplicate keys) or unknown/wrongly-typed fields.

Common situations: Hand-edited crypto-config.yaml with tab characters instead of spaces; missing OrdererOrgs/PeerOrgs sections; wrong types (e.g. Counts as string); YAML copied from docs with smart quotes; Windows line endings.

Related errors

• Error reading configuration: %s
• chaincode type not supported: %s
• failed to copy metadataDir directory folder: %s
• error unmarshalling YAML file %s: %s
• Error parsing template: %s

AI-assisted analysis of hyperledger/fabric@2736b63f8f (2026-09-04). Data as JSON: /api/errors/c6b2bd710b383b9a. Report an issue: GitHub.