Include order fixed.

CMakeLists.txt

 
 add_library(ScopeGuard INTERFACE)
 target_include_directories(ScopeGuard INTERFACE
-                       $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>
                        $<INSTALL_INTERFACE:include>
+                       $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>
                        )
 
 if( ENABLE_COMPAT_HEADER )