docker/cli · error

invalid type %T for healthcheck.test

Error message

invalid type %T for healthcheck.test

What it means

Error "invalid type %T for healthcheck.test" thrown in docker/cli.

Source

Thrown at cli/compose/loader/loader.go:892

	}
	panic(fmt.Errorf("expected a map or a list, got %T: %#v", mappingOrList, mappingOrList))
}

var transformShellCommand TransformerFunc = func(value any) (any, error) {
	if str, ok := value.(string); ok {
		return shlex.Split(str)
	}
	return value, nil
}

var transformHealthCheckTest TransformerFunc = func(data any) (any, error) {
	switch value := data.(type) {
	case string:
		return append([]string{"CMD-SHELL"}, value), nil
	case []any:
		return value, nil
	default:
		return value, fmt.Errorf("invalid type %T for healthcheck.test", value)
	}
}

var transformSize TransformerFunc = func(value any) (any, error) {
	switch value := value.(type) {
	case int:
		return int64(value), nil
	case string:
		return units.RAMInBytes(value)
	}
	panic(fmt.Errorf("invalid type for size %T", value))
}

var transformStringToDuration TransformerFunc = func(value any) (any, error) {
	switch value := value.(type) {
	case string:
		d, err := time.ParseDuration(value)
		if err != nil {

View on GitHub (pinned to e9452d6e78)

When it happens

Trigger: Thrown at cli/compose/loader/loader.go:892 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/4ab23e5b47aa0662.json. Report an issue: GitHub.