https://github.com/freeorion/freeorion/pull/5259
--- a/GG/GG/CMakeLists.txt
+++ b/GG/GG/CMakeLists.txt
@@ -20,3 +20,3 @@
         ${CMAKE_CURRENT_LIST_DIR}/Clr.h
-        ${CMAKE_CURRENT_LIST_DIR}/Config.h
+        ${CMAKE_CURRENT_BINARY_DIR}/Config.h
         ${CMAKE_CURRENT_LIST_DIR}/Control.h