Now builds, despite Apple gutting /usr/include and /usr/lib. It’ll default to the version of the SDK appropriate for your OS, and should work OK with 3rd party clang and gcc (after the hacks that just went in). case "$host" in *-darwin*) dnl # dnl # The version of GCC apple ships with Mavericks works out of the dnl # box, and presumably selects the highest version SDK for OSX. dnl # AC_MSG_CHECKING([if cc is apple llvm]) if ! $CC --version 2>&1 | grep -I 'Apple LLVM' > /dev/null; then AC_MSG_RESULT(no) AC_CHECK_PROG(SW_VERS, sw_vers, yes, no) AC_CHECK_PROG(XCODEBUILD, xcodebuild, yes, no) if test "x$SW_VERS" = "xyes" && test "x$XCODEBUILD" = "xyes"; then AC_MSG_NOTICE([determining OSX SDK path]) osx_sdk_path=$(xcodebuild -version -sdk macosx$(sw_vers -productVersion) Path) AC_MSG_RESULT([$osx_sdk_path]) dnl # dnl # We need to export these, else the child configure scripts all fail dnl # their compiler checks. dnl # export CFLAGS="--sysroot=$osx_sdk_path $CFLAGS" export CPPFLAGS="--sysroot=$osx_sdk_path $CPPFLAGS" export LDFLAGS="-L$osx_sdk_path/usr/lib/ $LDFLAGS" fi else AC_MSG_RESULT(yes) fi ;; Mmm crunchy. Let me know if this breaks older OSX versions. Arran Cudbard-Bell <a.cudbardb@freeradius.org> FreeRADIUS Development Team