static Class runLocalHot(S fileName) {
  File f = userFile("Documents/Hot Code/" + fileName);
  S code = loadTextFile(f);
  if (code == null)
    fail("File not found: " + f2s(f));
  printIndent("| ", code);
  
  print("Hotwiring \*fileName*/...");
  Class main = hotwireSource(code);
  print("Running!");
  callMain(main);
  ret main;
}