BUG: Mantis-1468: warning for debug build in SuperBuild

SuperBuild/CMakeLists.txt

@@ -34,6 +34,10 @@ set(CMAKE_MODULE_PATH
     ${CMAKE_MODULE_PATH}
     )
 
+if(CMAKE_BUILD_TYPE STREQUAL "Debug")
+  message(WARNING "The support of debug build in SuperBuild is incomplete, some dependencies such as NetCDF don't support it.")
+endif()
+
 include(ExternalProject)
 
 # Not needed as OTB Superbuild requires c++14 since version 6.2