It seems that Apple keeps on moving their tools around and the old solution of installing the command line tools are with using xcode-select -install doesn't work. In Mojave, xcode-select doesn't install anything anymore (the GUI always fails to find the package) and the command line tools don't install itself in /usr/ or /usr/local. Mac OS X & macOS names. As you can see from the list above, with the exception of the first OS X beta, all versions of the Mac operating system from 2001 to 2012 were all named after big cats.