title: clang erroneously prefixing source files
body: <p>When I build my (Swift) Xcode project I get the following error:</p>
  
  <pre><code>clang: error: no such file or directory: '/path/to/DerivedData/MyProject-btmqlitphlzsmgfdbhbzoygglxgm/Build/Intermediates/MyProject.build/Debug-iphonesimulator/MyProject.build/DerivedSources/CoreDataGenerated/MyProject/MyProject.MySourceFile+CoreDataProperties.m'
  clang: error: no input files
  </code></pre>
  
  <p>Notice the file it is complaining about is <code>MyProject.MySourceFile+CoreDataProperties.m</code>. If I go to that directory in the derived data I see the <em>actual</em> file is <code>MySourceFile+CoreDataProperties.m</code> without the <code>MyProject</code> prefix.</p>
  
  <p>This might have something to do with Cocoapods; my Podfile is as follows</p>
  
  <pre><code>source 'https://github.com/CocoaPods/Specs.git'
  platform :ios, '10.0'
  
  target 'MyProject' do
      use_frameworks!
      pod 'Alamofire', '~&gt; 4.0'
      pod 'AlamofireImage', '~&gt; 3.0'
      pod 'XCGLogger', :git =&gt; 'https://github.com/DaveWoodCom/XCGLogger.git', :branch =&gt; 'swift_3.0'
  end
  </code></pre>
  
  <p>I have recently migrated my project to Xcode 8 + Swift 3 and pulled in the updated dependencies for Swift 3.</p>