errs.go
func Format(info Info, format string, argv ...interface{}) Err {
	return newErr(debug.Stack(), fmt.Errorf(format, argv...), false, info, nil)
}
func Format(info Info, format string, argv ...interface{}) Err {
	return newErr(debug.Stack(), fmt.Errorf(format, argv...), false, info, nil)
}
// Format creates and wraps an error with the given error string. Equivalent to:
// `errs.Wrap(fmt.Errorf(format, args...))`