NullReferenceException when mocked method has a nullable value type argument, but It.IsAny constraint is not nullable

[ashmind]

Example:

public interface ISomeInterface {
    void DoSomething(Guid? guid);
}

mock.Setup(x => x.DoSomething(It.IsAny<Guid>()))
mock.Object.DoSomething(null);

Result:

System.NullReferenceException : Object reference not set to an instance of an object.
    at Moq.Match`1.Matches(Object value)
    at Moq.MethodCall.Matches(ICallContext call)
    at System.Linq.Enumerable.LastOrDefault(IEnumerable`1 source, Func`2 predicate)
    at Moq.ExtractProxyCall.HandleIntercept(ICallContext invocation, InterceptStrategyContext ctx)
    at Moq.Interceptor.Intercept(ICallContext invocation)
    at Castle.DynamicProxy.AbstractInvocation.Proceed()
    at Castle.Proxies.ISomeInterfaceProxy.DoSomething(Nullable`1 guid)

[anonymous112233]

This seem to back as of latest v. 4.2.1506.2016

[yrshaikh]

For those who are coming here in 2019. Try this

mock.Setup(x => x.DoSomething(It.IsAny<Guid?>()))

[stakx]

@yrshaikh: I'm mentioning the following just in case that there is a misunderstanding here: The difference between It.IsAny<Guid>() or It.IsAny<Guid?>() lies in whether or not you want to match null as well. In up-to-date versions of Moq, you should no longer see a NullReferenceException (which is what this issue was about) regardless of which form you choose.