Index: amcl/CMakeLists.txt
===================================================================
--- amcl.orig/CMakeLists.txt
+++ amcl/CMakeLists.txt
@@ -1,5 +1,7 @@
 cmake_minimum_required(VERSION 3.1)
 project(amcl)
+include(CheckSymbolExists)
+include(CheckIncludeFile)
 
 if(NOT CMAKE_CXX_STANDARD)
   set(CMAKE_CXX_STANDARD 11)