Building on Mac and tr1/type_traits not found

I’m having a problem trying to get past this issue.
The Mac OSX 10.11.4 + 10.11SDK etc etc. I know it’s not officially supported - but developers are working on it … and I’m seeking help from someone who may know about this, and how to get past it. I’m working on it for a week or more now, but have got lost.

This is a screen snap of the output of the error in XCode. The offending … code is actually in the /usr/local/include/wx-3.0-debug/wx/strvararg.h file, but also in the /usr/local/include/wx-3.1/wx/strvararg.h file.

Now, do I patch the WX file - or set a #define or #ifdef in the Audacity code somewhere.? Does anyone know or have an idea?

#if defined(HAVE_TYPE_TRAITS)
    #include <type_traits>
#elif defined(HAVE_TR1_TYPE_TRAITS)
    #ifdef __VISUALC__
        #include <type_traits>
        #include <tr1/type_traits>

These are the only instructions that I know of that work: