Missing Error Messages?

I don't seem be getting error messages for undefined symbols anymore. Just nothing happens, and I'm back to putting in console logs until I find the point where it stops (or notice the error while doing so)

I think I finally figured this out. I've been using promise based apis more, and both coherent promises (return from engine.call) and jQuery.Deferred will swallow errors in thens.

I made a hack for coherent promises:

Code:

var Promise = engine.createDeferred().constructor
Promise.prototype.make_chain = function (handler, promise, ok) {
  return function (result) {
    var handlerResult;
    try {
      handlerResult = handler.code.call(handler.context, result);
      if (handlerResult instanceof Promise) {
        handlerResult.merge(promise);
      } else if (this.state === ok) {
        promise.resolve(handlerResult);
      } else {
        promise.reject(handlerResult);
      }
    } catch (error) {
      console.log(error.stack) // *******
      promise.reject(error);
    }
  };
};