svoid tarInJar(File jarIn, File jarOut) ctex {
  print("tarInJar " + f2s(jarIn) + " => " + f2s(jarOut));
  temp ZipOutputStream zipOut = zipOutputStream(jarOut);
  zipOut.putNextEntry(new ZipEntry("bulk.tar"));
  zip2tar(jarIn, zipOut);
}

svoid tarInJar(File jarIn) {
  if (!fileExists(jarIn)) ret;
  File jarOut = fileInSameDirectory(jarIn, dropSuffixIC(".jar", jarIn.getName()) + ".repacked.jar");
  renameFileToUniqueName(jarOut); // backup old version
  tarInJar(jarIn, jarOut);
}

svoid tarInJar(S jarIn) {
  tarInJar(newFile(jarIn));
}