the standard release & RC builds work fine, but I needed to regenerate (i.e. clean out) the cmake directories in order to do git builds. After reinstalling xcode command line stuff & regenerating, FG builds fine, but there seems to be an issue with the QT I have installed (5.9.1) - I get a black launcher window.
I can start FG fine by selecting the place where I know the fly button is & it works fine, but I can't actually see anything in the launcher
Just upgrading my Qt installation to see if that helps... 2.8Gb later & we'll see how it goes