I faced same issue, in macOS Mojave (10.14.2) with Xcode 10.1
It seems that Xcode application need to allow for outbound connection
Steps to resolve
- System Preference -> Security & privacy -> Firewall
- Click on Lock icon & enter admin's credential to unlock it.
- Click firewall options
- Check "Automatically allow built-in software to receive incoming connection"
- Click "+" icon & add Xcode to it. (Make sure that you add correct Xcode version from which you are deploying build).
