Accessing any unknown variable inside worker, program is not responding at all.

[amrendra007]

var Worker = require("webworker-threads").Worker;

require("http")
  .createServer(function(req, res) {

var fibo = new Worker(function() {
  console.log('var', unknownvar)
  function fibo(n) {
    console.log('n', n)
    return n > 1 ? fibo(n - 1) + fibo(n - 2) : 1;
  }

  this.onmessage = function(event) {
    postMessage(fibo(event.data));
  };
});

fibo.onerror = function(error) {
  console.log('error', error)
}

fibo.onmessage = function(event) {
  res.end("fib result" + event.data);
};

fibo.postMessage(10);

})
.listen(8001);

I am trying to access some unknown variable with this

>console.log('var', unknownvar)

and this code is not responding anything , its not working also. It becomes difficult to debug what is going on without any response.