Spider sample code not executing properly

[Zacqary]

I tried to run the sample code on spiderlang.org (with a modification so it didn't depend on a global function that wasn't there)

fn TimeMachine(pilot) {
  this.pilot = pilot;

  this.go = fn (noise) {
    ::console.log(noise);
  };
}

fn Tardis()
  extends TimeMachine("The Doctor") {

  this.go = () =>
    super.go("vorp vorp");
}

fn DeLorean()
  extends TimeMachine("Marty") {

  this.go = () =>
    super.go("One point twenty-one gigawatts!");
}

fn getTimeMachines(){
    return [new Tardis(), new DeLorean()];
}

for timeMachine in getTimeMachines() {
  timeMachine?.go();
}

But this throws an error:

/usr/local/lib/node_modules/spider-script/cli.js:92
        vm.runInNewContext(compilerOutput.result, sandbox);
           ^
TypeError: Property '__$503654756$5$__' of object object is not a function
    at evalmachine.<anonymous>:30:81
    at Object.ModuleStore.getAnonymousModule (/usr/local/lib/node_modules/spider-script/node_modules/traceur/bin/traceur.js:953:30)
    at evalmachine.<anonymous>:1:29
    at /usr/local/lib/node_modules/spider-script/cli.js:92:12
    at fs.js:272:14
    at Object.oncomplete (fs.js:108:15)

Whereas this code runs fine:

getTimeMachines()[0].go();
getTimeMachines()[1].go();

So it looks like something's going on with the way for in loops are being compiled.

Is this a bug in Spider or did I get the install instructions wrong?

[Zacqary]

Tried compiling to ES6, then running with Babel, and it works. Looks like something's up with Traceur.