title: CMake seems to ignore CMAKE_OSX_DEPLOYMENT_TARGET
body: <p>I'm using CMake 3.3.2 and Xcode 7.1 on OS X 10.10.5.</p>
  
  <p>I have a small C++ project that uses CMake. I want it to run on OS X 10.9 or later. So I modified my CMakeLists.txt to look start this:</p>
  
  <pre><code>cmake_minimum_required(VERSION 3.3)
  set(CMAKE_OSX_DEPLOYMENT_TARGET "10.9")
  
  project(...
  </code></pre>
  
  <p>Then I create the Xcode project like this:</p>
  
  <pre><code>cmake -G Xcode &lt;path&gt;
  </code></pre>
  
  <p>However, the resulting xcodeproj bundle doesn't seem to have a deployment target set. When I open the contained project.pbxproj file in a text editor, there is no line mentioning <code>MACOSX_DEPLOYMENT_TARGET</code>.</p>
  
  <p>Accordingly, when I open the project in Xcode, under Build Settings > Deployment > OS X Deployment Target, Xcode always displays the default value "OS X 10.11", no matter what I specify in CMakeLists.txt. When I manually change the setting in Xcode and then re-open the project file in a text editor, the line <code>MACOSX_DEPLOYMENT_TARGET = 10.9;</code> has correctly been added.</p>
  
  <p>Am I doing something wrong? Googling the problem didn't give any recent results.</p>