CMake: Fail-fast if the used CMake version is too old for our Boost v…

…ersion

CMakeLists.txt

@@ -65,10 +65,18 @@ add_definitions(-DENABLE_CGAL)
 # NOTE FindCGAL.cmake resets the BOOST_* and Boost_* variables,
 #   because it looks for Boost itself, so it has to be called
 #   before we look for our own required boost libraries.
-find_package(Boost 1.36 REQUIRED COMPONENTS filesystem system thread regex program_options QUIET)
+set(BOOST_DIRECTLY_REQUIRED_LIBRARIES filesystem system thread regex program_options)
+find_package(Boost 1.36 REQUIRED COMPONENTS ${BOOST_DIRECTLY_REQUIRED_LIBRARIES} QUIET)
 message(STATUS "Boost: ${Boost_MAJOR_VERSION}.${Boost_MINOR_VERSION}.${Boost_SUBMINOR_VERSION}")
 include_directories(${Boost_INCLUDE_DIRS})
 
+# Check if boost dependency libraries have been found too
+list(LENGTH BOOST_DIRECTLY_REQUIRED_LIBRARIES BOOST_DIRECTLY_REQUIRED_LIBRARIES_LENGTH)
+list(LENGTH Boost_LIBRARIES Boost_LIBRARIES_LENGTH)
+if(Boost_LIBRARIES_LENGTH EQUAL BOOST_DIRECTLY_REQUIRED_LIBRARIES_LENGTH)
+  message(FATAL_ERROR "No dependent Boost libraries found. Your CMake (${CMAKE_VERSION}) version might be too old for the version of boost you are using (${Boost_MAJOR_VERSION}.${Boost_MINOR_VERSION}.${Boost_SUBMINOR_VERSION}). In that case, you should have received warnings above of the type: 'Imported targets not available for Boost version ${Boost_VERSION}'")
+endif()
+
 find_package(HarfBuzz 0.9.19 REQUIRED QUIET)
 message(STATUS "Harfbuzz: ${HARFBUZZ_VERSION}")
 include_directories(${HARFBUZZ_INCLUDE_DIRS})