1 !isEmpty(QMAKE_MAC_SDK) {

     2     !macx-xcode:!macx-pbuilder {

     3         QMAKE_CFLAGS += -isysroot $$QMAKE_MAC_SDK

     4         QMAKE_OBJECTIVE_CFLAGS += -isysroot $$QMAKE_MAC_SDK

     5         QMAKE_CXXFLAGS += -isysroot $$QMAKE_MAC_SDK

     6         QMAKE_LFLAGS += -Wl,-syslibroot,$$QMAKE_MAC_SDK

     7     }

     8 }