--- cmake/CMakeLists.txt.orig	2020-04-18 16:47:03 UTC
+++ cmake/CMakeLists.txt
@@ -163,6 +163,7 @@ if(USE_MMAP)
 endif()
 
 if (IFCXML_SUPPORT)
+    find_package(LibXml2 REQUIRED)
     add_definitions(-DWITH_IFCXML)
 endif()