Start possibilty for CMAKE_INSTALL_LIBDIR

CMakeLists.txt

@@ -16,7 +16,14 @@ SET( DD4hep_VERSION_PATCH 0 )
 # Basic project setup #
 #######################
 
-set ( CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} ${CMAKE_SOURCE_DIR}/cmake )
+set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} ${CMAKE_SOURCE_DIR}/cmake)
+
+if(NOT CMAKE_INSTALL_LIBDIR)
+  MESSAGE(STATUS "Setting CMAKE_INSTALL_LIBDIR to lib")
+  SET(CMAKE_INSTALL_LIBDIR lib)
+endif()
+MESSAGE(STATUS "CMAKE_INSTALL_LIBDIR=${CMAKE_INSTALL_LIBDIR}")
+
 
 IF(CMAKE_INSTALL_PREFIX_INITIALIZED_TO_DEFAULT)
   SET( CMAKE_INSTALL_PREFIX ${CMAKE_SOURCE_DIR} CACHE PATH