title: Inactive constraint becomes active?
body: <p>I've made a constraint in my storyboard and connected to a variable in my view controller. In <code>updateViewConstraints</code> I set the constraint's <code>active</code> property to false.</p>
  
  <p>When I do</p>
  
  <pre><code>self.view.setNeedsUpdateConstraints()
  self.view.layoutIfNeeded()
  </code></pre>
  
  <p>in <code>viewDidLoad</code>, <code>layoutIfNeeded</code> calls <code>updateViewConstraints</code> which sets the constraint to not active, but then somewhere after this it sets the constraint to active and then <code>UIViewAlertForUnsatisfiableConstraints</code> symbolic breakpoint is hit due to conflict with my other constraints. When I check the value of <code>.active</code> further up the stack at this breakpoint it is <code>true</code>.</p>
  
  <p>This only happens in <code>viewDidLoad</code>. Before the view is displayed on the screen <code>updateViewConstraints</code> is called again, and this time setting the constraint to not active sticks and the layout is correct. I still get the conflicting constraints error in the console. Is this a bug?</p>
  
  <p>Edit: Here's the stack trace leading to setting the constraint to active:
  <img src="https://i.stack.imgur.com/01heZ.png" alt="enter image description here"></p>