Index: CMakeLists.txt
--- CMakeLists.txt.orig
+++ CMakeLists.txt
@@ -273,7 +273,6 @@ endif()
 
 if (USE_GUI)
     find_package(TCL 8.5 REQUIRED)
-    find_package(TclStub 8.5 REQUIRED)
     find_package(Threads REQUIRED)
     if(APPLE)
           set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -framework AppKit")
@@ -423,7 +422,7 @@ if (USE_OCC)
       target_link_libraries(nggui PRIVATE Ws2_32.lib)
     endif(WIN32 AND USE_GUI)
     if(USE_GUI)
-      target_link_libraries(nggui PRIVATE occ_libs)
+      target_link_libraries(nggui PRIVATE occ_libs -L/usr/X11R6/lib)
     endif(USE_GUI)
 endif (USE_OCC)
 
@@ -445,6 +444,7 @@ endif (USE_MPEG)
 add_custom_target(ng_generate_version_file
   ${CMAKE_COMMAND}
     -DBDIR=${CMAKE_CURRENT_BINARY_DIR}
+    -DNETGEN_VERSION_GIT=${NETGEN_VERSION_GIT}
     -P ${CMAKE_CURRENT_LIST_DIR}/cmake/generate_version_file.cmake
     )
 #######################################################################
@@ -486,7 +486,7 @@ enable_testing()
 include(CTest)
 
 if(ENABLE_UNIT_TESTS)
-  include(${CMAKE_CURRENT_LIST_DIR}/cmake/external_projects/catch.cmake)
+  find_package(Catch2 REQUIRED)
 endif(ENABLE_UNIT_TESTS)
 
 
