Xamarin.iOS: System.ExecutionEngineException: Attempting to JIT compile method '(wrapper delegate-begin-invoke) System.IAsyncResult System.Func2<Library.SomeDelegate1<EEETestCase.AppDelegate>, bool>:begin_invoke_IAsyncResult__this___T_AsyncCallback_object (Library.SomeDelegate`1<EEETestCase.AppDelegate>,System.AsyncCallback,object)'

[rolfbjarne]

Steps to Reproduce

Run this project on an iOS device: eeetestcase2.zip

This looks very similar to #14972, but the difference is that in this case the offending code has to be in a referenced assembly. If it's included in the executable itself, the code works just fine.

This comes from VSTS #900808.

Current Behavior

An ExecutionEngineException, which is printed to the Application Output:

Got ExecutionEngineException when executing AsyncFire from referenced assembly: System.ExecutionEngineException: Attempting to JIT compile method '(wrapper delegate-begin-invoke) System.IAsyncResult System.Func`2<Library.SomeDelegate`1<EEETestCase.AppDelegate>, bool>:begin_invoke_IAsyncResult__this___T_AsyncCallback_object (Library.SomeDelegate`1<EEETestCase.AppDelegate>,System.AsyncCallback,object)' while running in aot-only mode. See https://docs.microsoft.com/xamarin/ios/internals/limitations for more information.

  at Library.DelegateHelper.AsyncFire[T] () [0x0000e] in <a300b5a252934c4d8462c65d592ee87e>:0 
  at EEETestCase.AppDelegate.FinishedLaunching (UIKit.UIApplication application, Foundation.NSDictionary launchOptions) [0x0002a] in /Users/rolf/Downloads/Archive/EEETestCase/Main.cs:35 

The app also turns red.

Expected Behavior

No ExecutionEngineException (and green screen).

Version Used:

xamarin/xamarin-macios@e89c3271f3c (which is mono/2019-02: bab25c0).

I can also reproduce with the current Xamarin.iOS stable (v12.8.0.2 / d16-0).

[marek-safar]

@vargaz any ideas why external reference can make a difference here?

/cc @SamMonoRT

[vargaz]

Wasn't this fixed by the fix for #14972 ?

[rolfbjarne]

This is working in in xamarin-macios/master (a7cb29a4b72405e62100babcc14645a6b6fe207f)