static void moveFileVerboseIfExists(File a, File b) {
  if (a == null || b == null) ret;
  if (!fileExists(a)) ret with print(a + " not found, skipping move");
  if (!renameFile(a, b))
    fail("File move failed: " + a + " to " + b);
  print("Moved: " + a + " to " + b);
}