当我运行"ionic cordova platform add ios"时,出现以下错误.怎么解决？
Exception: Using cordova-fetch for cordova-ios@0.0.1
Error: Failed to fetch platform cordova-ios@0.0.1
Probably this is either a connection problem, or platform spec is incorrect.
Check your connection and platform name/version/URL.
Error: npm: Command failed with exit code 1 Error output:
npm ERR! code ETARGET
npm ERR! notarget No matching version found for cordova-ios@0.0.1
npm ERR! notarget In most cases you or one of your dependencies are requesting
npm ERR! notarget a package version that doesn't exist. …