Kodi build fails /usr/local/lib/compat/libstdc++.so.6: version GLIBCXX_3.4.11 required

[Dave]

It seems Kodi requires  GLIBCXX_3.4.11 

/usr/local/lib/compat/libstdc++.so.6: version GLIBCXX_3.4.11 required by /usr/ports/multimedia/kodi/work/xbmc-c327c53/tools/depends/native/JsonSchemaBuilder/bin/JsonSchemaBuilder not found

I can't find anything in ports or packages which might install GLIBCXX_3.4.11

Anyone got any pointers for me?  Or is it broken?