Intermittent System.TypeLoadExceptions and System.Security.VerificationExceptions

Version: 7.3.1

Castle.Core version: 4.3.1.

After upgrading our solution from .NET 4.8 to .NET 6 we have seen intermittent (about one failed run in every 6-7 build server test runs) System.TypeLoadExceptions and System.Security.VerificationExceptions with the following messages:

System.Security.VerificationException example:

System.ArgumentException  GenericArguments[0], 'CompanyName.OurType[]', on 'T ExecuteLegacyQuery[T](CompanyName.IQuery`1[T])' violates the constraint of type 'T'.
---- System.Security.VerificationException  Method Castle.Proxies.ObjectProxy_35.ExecuteLegacyQuery type argument 'CompanyName.OurType[]' violates the constraint of type parameter 'T'.
   at System.RuntimeType.ValidateGenericArguments(MemberInfo definition, RuntimeType[] genericArguments, Exception e)
   at System.Reflection.RuntimeMethodInfo.MakeGenericMethod(Type[] methodInstantiation)
   at FakeItEasy.Core.MethodInfoManager.MakeGeneric(MethodInfo methodToMakeGeneric, MethodInfo originalMethod) in CprojectsfakeiteasysrcFakeItEasyCoreMethodInfoManager.csline 112
   at FakeItEasy.Core.MethodInfoManager.c__DisplayClass5_0.GetMethodOnTypeThatImplementsInterfaceMethodb__2(f__AnonymousType4`2 methodTargetPair) in CprojectsfakeiteasysrcFakeItEasyCoreMethodInfoManager.csline 102
   at System.Linq.Enumerable.WhereSelectEnumerableIterator`2.MoveNext()
   at System.Linq.Enumerable.TryGetFirst[TSource](IEnumerable`1 source, Boolean& found)
   at System.Linq.Enumerable.First[TSource](IEnumerable`1 source)
   at FakeItEasy.Core.MethodInfoManager.GetMethodOnTypeThatImplementsInterfaceMethod(Type type, MethodInfo method) in CprojectsfakeiteasysrcFakeItEasyCoreMethodInfoManager.csline 98
   at FakeItEasy.Core.MethodInfoManager.FindMethodOnTypeThatWillBeInvokedByMethodInfo(Type type, MethodInfo method) in CprojectsfakeiteasysrcFakeItEasyCoreMethodInfoManager.csline 46
   at FakeItEasy.Core.MethodInfoManager.c.GetMethodOnTypeThatWillBeInvokedByMethodInfob__2_0(TypeMethodInfoPair k) in CprojectsfakeiteasysrcFakeItEasyCoreMethodInfoManager.csline 41
   at System.Collections.Concurrent.ConcurrentDictionary`2.GetOrAdd(TKey key, Func`2 valueFactory)
   at FakeItEasy.Core.MethodInfoManager.GetMethodOnTypeThatWillBeInvokedByMethodInfo(Type type, MethodInfo method) in CprojectsfakeiteasysrcFakeItEasyCoreMethodInfoManager.csline 41
   at FakeItEasy.Creation.CastleDynamicProxy.CastleDynamicProxyInterceptionValidator.GetInvokedMethod(MethodInfo method, Object callTarget) in CprojectsfakeiteasysrcFakeItEasyCreationCastleDynamicProxyCastleDynamicProxyInterceptionValidator.csline 79
   at FakeItEasy.Creation.CastleDynamicProxy.CastleDynamicProxyInterceptionValidator.MethodCanBeInterceptedOnInstance(MethodInfo method, Object callTarget, String& failReason) in CprojectsfakeiteasysrcFakeItEasyCreationCastleDynamicProxyCastleDynamicProxyInterceptionValidator.csline 20
   at FakeItEasy.Creation.FakeObjectCreator.DefaultCreationStrategy.MethodCanBeInterceptedOnInstance(MethodInfo method, Object callTarget, String& failReason) in CprojectsfakeiteasysrcFakeItEasyCreationFakeObjectCreator.csline 184
   at FakeItEasy.Creation.FakeObjectCreator.MethodCanBeInterceptedOnInstance(MethodInfo method, Object callTarget, String& failReason) in CprojectsfakeiteasysrcFakeItEasyCreationFakeObjectCreator.csline 76
   at FakeItEasy.Configuration.DefaultInterceptionAsserter.AssertThatMethodCanBeInterceptedOnInstance(MethodInfo method, Object callTarget) in CprojectsfakeiteasysrcFakeItEasyConfigurationDefaultInterceptionAsserter.csline 19
   at FakeItEasy.Configuration.FakeConfigurationManager.AssertThatMemberCanBeIntercepted(ParsedCallExpression parsed) in CprojectsfakeiteasysrcFakeItEasyConfigurationFakeConfigurationManager.csline 96
   at FakeItEasy.Configuration.FakeConfigurationManager.CallTo[T](Expression`1 callSpecification) in CprojectsfakeiteasysrcFakeItEasyConfigurationFakeConfigurationManager.csline 46
   at FakeItEasy.A.CallTo[T](Expression`1 callSpecification) in CprojectsfakeiteasysrcFakeItEasyA.csline 161

System.TypeLoadException example:

System.TypeLoadException : GenericArguments[0], 'T', on 'Castle.Proxies.Invocations.ISqlDatabase_ExecuteQueryAsync_1[TEvent]' violates the constraint of type parameter 'TEvent'.
   at Castle.Proxies.ObjectProxy_63.ExecuteQueryAsync[T](String sql, Object param, CancellationToken cancellationToken, Nullable`1 commandTimeout)

The common part about all these exceptions is the error about violating the constraint of type parameter and that they are all related to mocks.

I don’t believe that this issue directly related to the FakeItEasy, but rather to the underlying library - Castle.Core.

Creating this issue for visibility.

Similar issue with moq4: https://github.com/moq/moq4/issues/1145

The issue on the Castle.Core side: https://github.com/castleproject/Core/issues/193

[blairconrad]

Thanks for continuing on this, @maxcherednik. I wonder, though. The leading though is that a problem is in or below the Castle.Core project, it may be a better use of your time to follow up exclusively in https://github.com/castleproject/Core/issues/193. Then you don’t have to duplicate your efforts, and people can read all the details in one place…

(The Castle.Core code is largely over my head, and I given work and home commitments, I doubt I’m going to get enough time to educate myself and start contributing in the near future.)

[blairconrad]

where does this generic parameter name coming from

No idea. FakeItEasy does not create (or change) generic parameters called “TEvent”, as far as I can tell. Nor does a quick search in GitHub reveal anything like that in the Castle.Core source.