docker/cli · error

unsupported Compose file version: %s

Error message

unsupported Compose file version: %s

What it means

Error "unsupported Compose file version: %s" thrown in docker/cli.

Source

Thrown at cli/compose/schema/schema.go:82

func normalizeVersion(version string) string {
	switch version {
	case "", "3":
		return defaultVersion
	default:
		return version
	}
}

//go:embed data/config_schema_v*.json
var schemas embed.FS

// Validate uses the jsonschema to validate the configuration
func Validate(config map[string]any, version string) error {
	version = normalizeVersion(version)
	schemaData, err := schemas.ReadFile("data/config_schema_v" + version + ".json")
	if err != nil {
		return fmt.Errorf("unsupported Compose file version: %s", version)
	}

	schemaLoader := gojsonschema.NewStringLoader(string(schemaData))
	dataLoader := gojsonschema.NewGoLoader(config)

	result, err := gojsonschema.Validate(schemaLoader, dataLoader)
	if err != nil {
		return err
	}

	if !result.Valid() {
		return toError(result)
	}

	return nil
}

func toError(result *gojsonschema.Result) error {

View on GitHub (pinned to e9452d6e78)

When it happens

Trigger: Thrown at cli/compose/schema/schema.go:82 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of docker/cli@e9452d6e78 (2026-08-01). Data as JSON: /data/errors/ad359aab4ed99d2c.json. Report an issue: GitHub.