svoid addToNativeLibraryPath(File dir) {
  if (dir == null) ret;
  S libraryPath = System.getProperty("java.library.path");
  if (contains(splitAt(libraryPath, File.pathSeparator), f2s(dir))) ret;
  libraryPath += File.pathSeparator + f2s(dir);
  print("New java.library.path: " + libraryPath);
  System.setProperty("java.library.path", libraryPath);
  
  // hack for newer JDKs
  // see https://stackoverflow.com/questions/15409223/adding-new-paths-for-native-libraries-at-runtime-in-java
  
  // set sys_paths to null so that java.library.path will be reevalueted next time it is needed
  setOpt(ClassLoader.class, sys_paths := null);
}