title: xcodebuild: error: unexpected duplicate task: CopyStringsFile
body: <p>I am updating latest full version Xcode 10, CocoaPods 1.5.3.</p>
  
  <p>I create chat library for my big project, I have multiple pod libraries in my chat library so I run pod install and it's working fine for building and running the app. But since my lib is used for others big projects I need to send my lib to github and pod.</p>
  
  <p>I have this error message when do pod validation before I send my lib 'pod spec lint'
  <strong>xcodebuild: error: unexpected duplicate task: CopyStringsFile</strong>
  due to localization. I have 7 languages with each strings files and it's error all of them. I am using this <a href="https://github.com/marmelroy/Localize-Swift" rel="nofollow noreferrer">Localize-Swift</a> to help localization far more easier.</p>
  
  <blockquote>
    <p>I already tried CocoaPods beta 1.6.0 it's not working too.</p>
  </blockquote>
  
  <p>What should I do?</p>