Only add the compile options to the dealii::dealii target

source/CMakeLists.txt

@@ -75,7 +75,19 @@ add_subdirectory(sundials)
 add_subdirectory(trilinos)
 add_subdirectory(arborx)
 
+#
+# Define a "dealii", i.e., "${DEAL_II_NAMESPACE}", target that contains
+# DEAL_II_CXX_FLAGS[_DEBUG|_RELEASE] and otherwsie aliases dealii_debug or
+# dealii_release depending on the downstream CMAKE_BUILD_TYPE.
+#
+
 add_library(${DEAL_II_NAMESPACE} INTERFACE)
+separate_arguments(_compile_options UNIX_COMMAND "${DEAL_II_CXX_FLAGS}")
+shell_escape_option_groups(_compile_options)
+target_compile_options(${DEAL_II_NAMESPACE} INTERFACE
+  $<$<COMPILE_LANGUAGE:CXX>:${_compile_options}>
+  )
+
 
 foreach(build ${DEAL_II_BUILD_TYPES})
   string(TOLOWER ${build} build_lowercase)
@@ -131,12 +143,22 @@ foreach(build ${DEAL_II_BUILD_TYPES})
     )
 
   separate_arguments(_compile_options UNIX_COMMAND
-    "${DEAL_II_CXX_FLAGS} ${DEAL_II_CXX_FLAGS_${build_uppercase}}"
+    "${DEAL_II_CXX_FLAGS_${build_uppercase}}"
     )
   shell_escape_option_groups(_compile_options)
-  target_compile_options(${DEAL_II_NAMESPACE}_${build_lowercase} PUBLIC
-    $<$<COMPILE_LANGUAGE:CXX>:${_compile_options}>
+  if(${build_lowercase} MATCHES "debug")
+    target_compile_options(${DEAL_II_NAMESPACE} INTERFACE
+      "$<$<CONFIG:Debug>:$<$<COMPILE_LANGUAGE:CXX>:${_compile_options}>>"
+      )
+    target_compile_options(${DEAL_II_NAMESPACE} INTERFACE
+      "$<$<CONFIG:>:$<$<COMPILE_LANGUAGE:CXX>:${_compile_options}>>"
+      )
+  endif()
+  if(${build_lowercase} MATCHES "release")
+    target_compile_options(${DEAL_II_NAMESPACE} INTERFACE
+      "$<$<CONFIG:Release>:$<$<COMPILE_LANGUAGE:CXX>:${_compile_options}>>"
     )
+  endif()
 
   if(CMAKE_SYSTEM_NAME MATCHES "Darwin")
     set_target_properties(${DEAL_II_NAMESPACE}_${build_lowercase}