// output variable, set even when compilation fails
static new ThreadLocal<S> transpileAndCompileForHotwiring_src;

static File transpileAndCompileForHotwiring(S src, LS libs default null) {
  transpileAndCompileForHotwiring_src.set(null);
  
  // taken from veryQuickJava3
  if (libs == null) libs = new L;
  src = transpileRaw(src); // transpiled, with lib references
  transpileAndCompileForHotwiring_src.set(src);
  
  // taken from veryQuickJava_finish
  src = findTranslators2(src, libs);
  S dehlibs = join(" ", libs);
  File bytecode = javaCompile_overInternalBot(src, dehlibs);
  print(+bytecode);
  print("Files: " + listZip(bytecode));
    
  ret bytecode;
}

Began life as a copy of #1031279