As some of you probably know, the code does not compile when you upgrade to XCode 8. An example error message is:
quickstep/third_party/glog/src/raw_logging.cc:153:3: 'syscall' is deprecated: first deprecated in macOS 10.12 - syscall(2) is unsupported; please switch to a supported interface. For SYS_kdebug_trace use kdebug_signpost(). So, don’t rush to upgrade to XCode 8. Cheers, Jignesh