How to disable building glbinding::glbinding-aux?

In my root CMakeLists.txt I:

```
# glbinding
set(OPTION_BUILD_TOOLS OFF CACHE BOOL "" FORCE)
set(OPTION_BUILD_EXAMPLES OFF CACHE BOOL "" FORCE)
add_subdirectory(external/glbinding/)
```

And then I only link:

```
target_link_libraries(${PROJECT_NAME} PRIVATE
glbinding::glbinding
glfw
)
```

(note the missing `glbinding::glbinding-aux` linking)

But it seems like I'm missing an option or something and the `glbinding-aux` lib still gets built anyway just from adding this repo as a subdirectory:

```
...
[ 87%] Building CXX object external/glbinding/source/glbinding-aux/CMakeFiles/glbinding-aux.dir/source/Meta_FunctionStringsByExtension.cpp.obj
[ 88%] Building CXX object external/glbinding/source/glbinding-aux/CMakeFiles/glbinding-aux.dir/source/Meta_FunctionStringsByVersion.cpp.obj
[ 89%] Building CXX object external/glbinding/source/glbinding-aux/CMakeFiles/glbinding-aux.dir/source/Meta_ReqVersionsByExtension.cpp.obj
[ 90%] Building CXX object external/glbinding/source/glbinding-aux/CMakeFiles/glbinding-aux.dir/source/Meta_StringsByBitfield.cpp.obj
[ 91%] Building CXX object external/glbinding/source/glbinding-aux/CMakeFiles/glbinding-aux.dir/source/Meta_StringsByBoolean.cpp.obj
[ 92%] Building CXX object external/glbinding/source/glbinding-aux/CMakeFiles/glbinding-aux.dir/source/Meta_StringsByEnum.cpp.obj
[ 93%] Building CXX object external/glbinding/source/glbinding-aux/CMakeFiles/glbinding-aux.dir/source/Meta_StringsByExtension.cpp.obj
[ 93%] Building CXX object external/glbinding/source/glbinding-aux/CMakeFiles/glbinding-aux.dir/source/ValidVersions_list.cpp.obj
[ 94%] Building CXX object external/glbinding/source/glbinding-aux/CMakeFiles/glbinding-aux.dir/source/debug.cpp.obj
...
```

and it takes soooooo long to build. I'd prefer not to.

Is there just an option similar to `OPTION_BUILD_TOOLS ` / `OPTION_BUILD_EXAMPLES` to disable building it? Could it be added? Thanks.