title: Contradicting iOS runtime constraint error
body: <p>I am getting an unsatisfiable constraints error at runtime (iOS 8.3, XCode 6.3, iPad Air simulator), but the error itself is contradicting with the data that I observe in View Hierarchy debugger.</p>
  
  <p>The runtime error:</p>
  
  <pre><code>"&lt;NSLayoutConstraint:0x7fd7b96a8e30 V:[PushDownView:0x7fd7b96a8890(100)]&gt;",
  "&lt;NSLayoutConstraint:0x7fd7b943fa00 V:[UIView:0x7fd7b943f7d0(80)]&gt;",
  "&lt;NSLayoutConstraint:0x7fd7b96ac9a0 V:|-(0)-[PushDownView:0x7fd7b96a8890]   (Names: '|':UIView:0x7fd7b943f7d0 )&gt;",
  "&lt;NSLayoutConstraint:0x7fd7b96ad3a0 PushDownView:0x7fd7b96a8890.bottom == UIView:0x7fd7b943f7d0.bottom&gt;"
  
  Will attempt to recover by breaking constraint 
  &lt;NSLayoutConstraint:0x7fd7b96a8e30 V:[PushDownView:0x7fd7b96a8890(100)]&gt;
  </code></pre>
  
  <p>In Visual Hierarchy debugger, I select the constraints listed above and view them in Object inspector. Here they are in order or appearance:</p>
  
  <pre><code>Address: 0x7fd7b96a8e30
  First Item: PushDownView
  Relation: Equal
  Multiplier: 1
  Constant: 100
  Priority: 76
  
  Address: 0x7fd7b943fa00
  First Item: UIView
  Relation: Equal
  Multiplier: 1
  Constant: 100
  Priority: 76
  
  Address: 0x7fd7b96ac9a0
  First Item: PushDownView
  Relation: Equal
  Multiplier: 1
  Constant: 0
  Priority: 76
  
  Address: 0x7fd7b96ad3a0
  First Item: PushDownView
  Relation: Equal
  Multiplier: 1
  Constant: 0
  Priority: 76
  </code></pre>
  
  <p>Look at the constraint <code>0x7fd7b943fa00</code> - the error claims it's setting UIView's height to 80. But the Object inspector claims the constant is 100. </p>
  
  <p>As far as I know, I set everything to be 100 in code (but I might be mistaken, so let's stick to facts here).</p>
  
  <p>What am I missing here? Why the error's and the Visual Hierarchy inspector's values are different?</p>