Do you want the application “Xcode.app” to accept incoming network connections

If you have to allow every time you runs Xcode..

here is the soluation

1. Open command tool

   

2. sudo /usr/libexec/ApplicationFirewall/socketfilterfw --setglobalstate off

3. /usr/libexec/ApplicationFirewall/socketfilterfw --add /Applications/Xcode.app/Contents/MacOS/Xcode

4. /usr/libexec/ApplicationFirewall/socketfilterfw --add /Applications/Xcode.app/Contents/Developer/Applications/iOS\ Simulator.app/Contents/MacOS/iOS\ Simulator

5. sudo /usr/libexec/ApplicationFirewall/socketfilterfw --setglobalstate on

then restart your system