Create a copy of method from IL

I am trying to create a copy of a method during runtime using reflection.

I have the following code.

public static R CopyMethod<T, R>(Func<T, R> f, T t)
{
    AppDomain currentDom = Thread.GetDomain();
    AssemblyName asm = new AssemblyName();
    asm.Name = "DynamicAssembly";
    AssemblyBuilder abl = currentDom.DefineDynamicAssembly(asm, AssemblyBuilderAccess.Run);
    ModuleBuilder mbl = abl.DefineDynamicModule("Module");
    TypeBuilder tbl = mbl.DefineType("Type");
    var info = f.GetMethodInfo();
    MethodBuilder mtbl = tbl.DefineMethod(info.Name, info.Attributes, info.CallingConvention, info.ReturnType, info.GetParameters().Select(x => x.ParameterType).ToArray());

    byte[] il = f.Method.GetMethodBody().GetILAsByteArray();

    mtbl.CreateMethodBody(il, il.Length);
    Type type = tbl.CreateType();
    Func<T, R> method = type.GetMethod(info.Name).CreateDelegate(typeof(Func<T, R>)) as Func<T, R>;
    return method(t);
}

The last line throws an exception with message "Common Language Runtime detected an invalid program".

I am testing with a very simple method (one line: return 10;).

Is there another way of doing this? I would prefer being able to get the parse tree of the method instead of using IL directly.