Observing UITextField text interferes with becomeFirstResponder()

[creister]

Discovered this while trying to select subsequent text field during textFieldShouldReturn.
I think this is an issue in Bond as well, I saw it there first.

import UIKit
import ReactiveUIKit

class ViewController: UIViewController {

  @IBOutlet weak var textField1: UITextField!
  @IBOutlet weak var textField2: UITextField!

  override func viewDidLoad() {
    super.viewDidLoad()

    textField1.delegate = self
    textField2.delegate = self

    // by observing textField2 we can't make it first responder when
    // textField1 should return.
    textField2.rText.observe { text in
      print(text)
    }
  }

}

extension ViewController: UITextFieldDelegate {
  func textFieldShouldReturn(textField: UITextField) -> Bool {
    if textField == textField1 {
      textField2.becomeFirstResponder()
    }
    return true
  }
}

[jbeachwood]

I am experiencing this exact same issue when attempting to bind an Observable to a UITextfield. A textfield that has had an Observable bound to it will not become the first responder.