cmake: check if the cmake module has been initialized

CMakeLists.txt

@@ -5,6 +5,11 @@
 
 CMAKE_MINIMUM_REQUIRED(VERSION 2.6)
 
+# Check if the submodule cmake have been initialized
+IF(NOT EXISTS "${PROJECT_SOURCE_DIR}/cmake/base.cmake")
+  MESSAGE(FATAL_ERROR "\nPlease run the following command first:\ngit submodule update --init\n")
+ENDIF()
+
 INCLUDE(cmake/base.cmake)
 INCLUDE(cmake/boost.cmake)
 INCLUDE(cmake/python.cmake)