What is the problem or limitation you are having?

Briefcase currently includes a verification check that Xcode is available. However, just installing Xcode isn't enough; it is necessary to install an iOS SDK and simulator. Without an SDK and simulator, Briefcase can't start an iOS app.

Describe the solution you'd like

As part of the Xcode verification check, there should be a check performed that an iOS SDK has been installed, and that a simulator is available; and if it isn't, display instructions on how to download the iOS SDK.

Describe alternatives you've considered

It might be worth splitting the Xcode check into 2 parts - one for Xcode, and one for iOS.

Additional context

I'm not 100% sure what mechanical check can be performed here. Two possible candidates are:

• xcrun --show-sdk-path --sdk iphoneos
• xcrun simctl list runtimes

The complication is that once you've got an iOS SDK, you can't verify if a verification check works... because you have an iOS SDK. We need to verify these steps on a "clean" box that hasn't had an iOS SDK installed.