當運行Xcode時，程序顯示
[Client] Updating selectors failed with: Error Domain=NSCocoaErrorDomain Code=4099 "The connection to service on pid 0 named com.apple.commcenter.coretelephony.xpc was invalidated." UserInfo={NSDebugDescription=The connection to service on pid 0 named com
這個錯誤時，說明是你開啟了全局代理，而去訪問局域網資源。
解決辦法：關閉打印。在終端輸入以下一句即可關閉打印。
xcrun simctl spawn booted log config --mode "level:off" --subsystem com.apple.CoreTelephony