release 12 out-of-tree build problem

Since release 11, there was the "llvmbuildectomy" change. I think I have the CMakeLists.txt files for my experimental backend correct. Is there anything else I need to do? I get the following error from cmake:

  -- Targeting My66000
CMake Error at cmake/modules/AddLLVM.cmake:760 (set_property):
   set_property could not find TARGET My66000. Perhaps it has not yet been
   created.
Call Stack (most recent call first):
   cmake/modules/AddLLVM.cmake:1318 (add_llvm_component_library)
   lib/Target/My66000/CMakeLists.txt:12 (add_llvm_target)
... and many more ...

What does "Perhaps it has not yet been created mean and how do I fix it?

Thanks,
brian

Never mind. I was missing a line add_llvm_component_group(...
in my top level CMakeLists.txt.
Sorry for the noise in the list.

brian