Hello again 9fans, I'm also trying to compile hosted Inferno for OS X 10.9, all seems to go well until the "mk install" giving this error message: shanes-air-2:inferno-os boris$ PATH=`pwd`/MacOSX/386/bin:$PATH mk install (cd lib9; mk install) cc -c -arch i386 -mmacosx-version-min=10.4 -Wno-deprecated-declarations -Wuninitialized -Wunused -Wreturn-type -Wimplicit -Wno-four-char-constants -Wno-unknown-pragmas -pipe -fno-strict-aliasing -no-cpp-precomp -mno-fused-madd -I/Users/boris/Documents/inferno-os/MacOSX/386/include -I/Users/boris/Documents/inferno-os/include -Os convD2M.c clang: error: unknown argument: '-mno-fused-madd' [-Wunused-command-line-argument-hard-error-in-future] clang: note: this will be a hard error (cannot be downgraded to a warning) in the future mk: cc -c -arch ... : exit status=exit(1) mk: for j in ... : exit status=exit(1) shanes-air-2:inferno-os boris$ Does anyone have any insight? Many thanks! Shane.