title: xcodebuild couldn't read dependency graph from ... .... : Permission denied
body: <p>Today I experienced the following error from xcodebuild:</p>
  
  <blockquote>
    <p>xcodebuild couldn't read dependency graph from ... .... : Permission denied</p>
  </blockquote>
  
  <p>And further down:</p>
  
  <blockquote>
    <p>Details:  unable to write dependency graph: You don’t have permission to save the file “my-app.build” in the folder “my-target-iphoneos”.</p>
  </blockquote>
  
  <p>I am documenting this since the cause is really obscure, see my answer.</p>