There seems to be problems with promises in can.Components and stache templates when using nw.js
The simplest way I can demonstrate the problem is with the following:
app.js
const AppViewModel = Map.extend({
  define: {
    message: {
      value: 'Hello World!',
      serialize: false
    },
    title: {
      value: 'NW.js Test',
      serialize: false
    },
	testPromise: {
		value: function() {
			return new Promise(function(resolve, reject) {
				// do nothing
			});
		}
	}
  }
});
index.stache
<h1>{{message}}</h1>
{{#if testPromise.isResolved}}
Test
{{else}}
Loading...
{{/if}}
When running using “donejs develop”, the page will show “Loading…” as expected. When running under nw.js the page will be blank (not even “Hello World!” is displayed)