Add comment explaining why bootstrapping cuda is now a two-step proce…

…ss [no ci]

CMakeLists.txt

@@ -74,7 +74,14 @@ morpheus_utils_initialize_package_manager(
 )
 
 # Initialize CUDA
-# NOTE: This MUST occur before any 'project' calls because of rapids_cmake requirements.
+# This is a two-step process. We need to call morpheus_utils_initialize_cuda_arch which in turn calls
+# rapids_cuda_init_architectures prior to calling project(). This is because rapids_cuda_init_architectures defines a
+# `CMAKE_PROJECT_<PROJECT-NAME>_INCLUDE` hook which is invoked by the project() call. This hook is what allows us to
+# set `CMAKE_CUDA_ARCHITECTURES=rapids` when performing a release build which will be expanded to the current list of
+# supported architectures by our version of rapids.
+#
+# After the call to project() we can then call morpheus_utils_enable_cuda() which will set some CUDA+clang settings
+# which can only be performed after calling project(), but which must be set prior to calling enable_language(CUDA)
 if(DEFINED MORPHEUS_CUDA_ARCHITECTURES)
   set(CMAKE_CUDA_ARCHITECTURES "${MORPHEUS_CUDA_ARCHITECTURES}")
 endif()
@@ -89,7 +96,7 @@ project(morpheus
   LANGUAGES C CXX
 )
 
-# Configure CUDA architecture
+# This sets some clang specific settings for CUDA prior to calling enable_language(CUDA)
 morpheus_utils_enable_cuda()
 
 rapids_cmake_write_version_file(${CMAKE_BINARY_DIR}/autogenerated/include/morpheus/version.hpp)