unittest.cs

public void DynamicLocalCapturedByLambda()
{
   var mslib = @"
      namespace System
      {
         public class Object { }
         public struct Int32 { }
         public class ValueType { }
         public class Attribute { }
         public struct Void { }
         public struct IntPtr { }
         public class Type {
            public static Type GetTypeFromHandle(RuntimeTypeHandle handle ) { return null; }
         }
         public struct RuntimeTypeHandle { }
         public class String { }
         public delegate void Action();
         public class MulticastDelegate : Delegate { }
         public class Delegate { }
      }";

   var source = @"
      class C
      {
         void M()
         {
            dynamic local = 42;
            System.Action lambda = () => {
               dynamic i = local;
            };
         }
      }
   ";
   // Build an mscorlib including String
   var mslibComp = CreateCompilation(new string[] { mslib }).VerifyDiagnostics();
   var mslibRef = mslibComp.EmitToImageReference();

   var comp = CreateCompilation(source, references: new[] { mslibRef, CSharpRef});
   comp.VerifyDiagnostics();

   CompileAndVerify(comp);
}