title: macos - installing xcode 9.2 on macOS 10.13
body: <p>and i saw the xcode 9.2 is run on macOS 10.12.6 and i have macOS 10.13 
  so i downloaded xcode 9.2.
  and while installing i will get this error</p>
  
  <p><a href="https://i.stack.imgur.com/kszzu.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/kszzu.png" alt="enter image description here"></a></p>
  
  <p>so how can i fix this error?
  or if is not running on my macOS version is there any trick to install that?</p>