message: Silence "unused" warning for strerror_r
diff: @@ -3111,7 +3111,7 @@ current_zone()
  {
  std::ostringstream os;
  char message[128];
  - strerror_r(errno, message, 128);
  + (void)strerror_r(errno, message, 128);
  os << "realpath failure: errno = " << errno << "; " << message;
  throw std::runtime_error(os.str());
  }
  