Circular base class dependency error when using nant but not Visual Studio

Question

I have a C# project that compiles fine in Visual Studio, but when I use a nant build script I get the following error:

"error CS0146: Circular base class dependency involving ClassA and BaseClassA"

Here is the structure of the classes:

BaseClassA : IEnumerable<ClassA.ClassB>
{
}

----

ClassA : BaseClassA
{
  ClassB
  {}
}

I understand the circular dependency part but VS is doing something to allow that to work. I would like to keep this structure and it compiles fine in Visual Studio. My question is, why is not compiling in nant and what can I do so it will compile in nant?