here is an app https://gist.github.com/gre/52e28f74eda0beccc17e880efe18c250
There is intentionally a bug in this app: the App component returns `<Demo setVariables={v=>this.setState(..)} variables={..} />` and `Demo` calls `setVariables` in componentDidMount and componentWillReceiveProps (it shouldn't, this is bad user code). What this issue raises is a regression behaviour in React 16 compared to 15.


in React 15 : it renders but you directly get a `Uncaught RangeError: Maximum call stack size exceeded`.
in React 16 : nothing renders, the app never loads and the browser is spinning forever! I think React is stuck in an infinite recursion.

I presume this is because fiber is by nature async. The fact things never ends makes it very hard to investigate and isolate the source of the problem in a large codebase.
should there be some sort of maximum call stack in Fiber ?

> Context: When we migrated our app to latest React Native recently, we had a weird freezing case: the app was completely unresponsive (no button works) but you could still do native actions like scroll a ScrollView. however, even the RN devtool menu action was not working (like the inspector) – probably because it involves JS and React was just stuck in this recursion loop.
In our case, the issue was because calling `relay.setVariables` in lifecycle but with a wrong logic. for some reason our code used to work in the past but now creates this recursion loop.
return <div>{this.state.x}</div>;
      }
    }
    var instance = ReactTestUtils.renderIntoDocument(<Component />);
    expect(instance.state.x).toBe(0);
    var innerCallbackRun = false;
    ReactDOM.unstable_batchedUpdates(function() {
      instance.setState({x: 1}, function() {
        instance.setState({x: 2}, function() {
          expect(this).toBe(instance);
          innerCallbackRun = true;
          expect(instance.state.x).toBe(2);
          expect(updateCount).toBe(2);
        });
        expect(instance.state.x).toBe(1);
        expect(updateCount).toBe(1);
      });
      expect(instance.state.x).toBe(0);
      expect(updateCount).toBe(0);
    });
    expect(innerCallbackRun).toBeTruthy();
    expect(instance.state.x).toBe(2);
    expect(updateCount).toBe(2);
  });
  it('should batch forceUpdate together', () => {
    var shouldUpdateCount = 0;
    var updateCount = 0;
    class Component extends React.Component {