debug why OSX_BIN_DIR is blank

CMakeLists.txt

@@ -271,10 +271,10 @@ elseif(APPLE)
     SET(CPACK_GENERATOR "DragNDrop")
     if ("${CMAKE_BUILD_TYPE}" STREQUAL "" OR "${CMAKE_BUILD_TYPE}" STREQUAL "RELEASE")
        set(OSX_BIN_DIR, "${CMAKE_BINARY_DIR}/bin_release")
-       message("DEBUG installer build, OSX_BIN_DIR=${OSX_BIN_DIR}")
+       message("DEBUG installer build, CMAKE_BINARY_DIR=${CMAKE_BINARY_DIR} OSX_BIN_DIR=${OSX_BIN_DIR}")
     else()
        set(OSX_BIN_DIR, "${CMAKE_BINARY_DIR}/bin_debug")
-       message("RELEASE installer build, OSX_BIN_DIR=${OSX_BIN_DIR}")
+       message("RELEASE installer build, CMAKE_BINARY_DIR=${CMAKE_BINARY_DIR} OSX_BIN_DIR=${OSX_BIN_DIR}")
     endif()
     install(FILES ${PROJECT_SOURCE_DIR}/output/resources.cfg DESTINATION ./)
     install(FILES ${PROJECT_SOURCE_DIR}/output/plugins.cfg DESTINATION ./)