**Do you want to request a _feature_ or report a _bug_?**

Report a bug.

**What is the current behavior?**

When testing components, `Warning: ReactComponentTreeDevtool: Missing React element for debugID 1 when building stack` is shown when calling `TestUtils.renderIntoDocument`.

**If the current behavior is a bug, please provide the steps to reproduce and if possible a minimal demo of the problem via https://jsfiddle.net or similar (template: https://jsfiddle.net/reactjs/69z2wepo/).**

https://github.com/angusfretwell/reproduce-debugid-warning (`npm install && npm test`).

**What is the expected behavior?**

According to #7187 this is an internal warning and shouldn't be displayed.

**Which versions of React, and which browser / OS are affected by this issue? Did this work in previous versions of React?**
- react@15.2.1
- react-addons-test-utils@15.2.1
- react-dom@15.2.1

I didn't receive this warning on 15.2.0.

var containerNode = ReactDOM.findDOMNode(parentInstance);
  var statusDisplayNodes = containerNode.childNodes;
  var i;
  var orderedDomIDs = [];
  for (i = 0; i < statusDisplayNodes.length; i++) {
    var inst = ReactDOMComponentTree.getInstanceFromNode(statusDisplayNodes[i]);
    orderedDomIDs.push(inst._rootNodeID);
  }
  var orderedLogicalIDs = [];
  var username;
  for (username in statusDisplays) {
    if (!statusDisplays.hasOwnProperty(username)) {
      continue;
    }
    var statusDisplay = statusDisplays[username];
    orderedLogicalIDs.push(
      ReactInstanceMap.get(statusDisplay)._renderedComponent._rootNodeID
    );
  }
  expect(orderedDomIDs).toEqual(orderedLogicalIDs);
}
/**
 * Todo: Check that internal state is preserved across transitions
 */
function testPropsSequence(sequence) {