Debugging Xamarin.iOS apps with Xcode

There might be scenarios where you want to use Xcode to debug some parts of your Xamarin.iOS application. While you will not be able to debug the .NET code in it, you will still be able to debug native code and use some of the native visualizers in Xcode.

Walkthrough

While there is no built-in support for Xcode debugging in Visual Studio for Mac, you can use the following steps to achieve this:

1. Create an Xcode iOS app with the same bundle ID as the one in your Xamarin app.

   • You can find your Xamarin.iOS project's bundle identifier by opening the Info.plist file:

     

   • In Xcode, you set the bundle identifier when creating your project or by selecting your target in the project:

     

2. Change the Xcode project to wait for launch instead of launching the app automatically:

   • Open the Edit Scheme Panel by selecting Product > Scheme > Edit Scheme or using the cmd⌘ + < keyboard shortcut.

   • Select the Run scheme, and in the right panel you should see Launch options. Select Wait for executable to be launched and click Close.

     

3. Run the Xcode project.

   This will install the dummy Xcode app on your device, but will not launch it.

4. Run the Xamarin app.

   Xcode should attach to the Xamarin app when it launches.

Caveats

You might have to make a small change to the Xamarin.iOS app every time you launch. Otherwise, Visual Studio for Mac will detect that the app doesn't need to be built and is already installed, and it won't reinstall it over the Xcode dummy app.

Alternative - using lldb

If you are comfortable with using lldb from the command line, there's a much simpler solution.

On the shell, type the following command:

touch ~/.mtouch-launch-with-lldb

You will get instructions in the Application Output window on what to do, but basically, when you run your application, you will be able to use lldb from the command line to debug your application.