Index: /trunk/Config.kmk
===================================================================
--- /trunk/Config.kmk	(revision 75623)
+++ /trunk/Config.kmk	(revision 75624)
@@ -2277,6 +2277,12 @@
  endif
  ifdef VBOX_WITH_NEW_XCODE
-   override TOOL_StandardDTrace_DTRACE := $(TOOL_$(VBOX_GCC_TOOL)_ENV_SETUP) dtrace "-xcpppath=$(VBOX_PATH_MACOSX_DEVEL_ROOT)/usr/bin/gcc"
-   export PATH:=$(VBOX_PATH_MACOSX_SDK)/usr/bin:$(PATH)
+  # For MacOS Mojave (and probably newer) we need a more recent XCode from the system.
+  # So just drop the tool environment and use the system's XCode instead.
+  TOOL_StandardDTrace_DTRACE_ENV_SETUP:=
+  if $(KBUILD_HOST_VERSION_MAJOR) < 18 # (OS X 10.14 Mojave)
+   TOOL_StandardDTrace_DTRACE_ENV_SETUP=$(TOOL_$(VBOX_GCC_TOOL)_ENV_SETUP)
+  endif
+  override TOOL_StandardDTrace_DTRACE := dtrace $(TOOL_StandardDTrace_DTRACE_ENV_SETUP) "-xcpppath=$(VBOX_PATH_MACOSX_DEVEL_ROOT)/usr/bin/gcc"
+  export PATH:=$(VBOX_PATH_MACOSX_SDK)/usr/bin:$(PATH)
  else
   if  $(VBOX_XCODE_VERSION_MAJOR) > 4 || ($(VBOX_XCODE_VERSION_MAJOR) == 4 && $(VBOX_XCODE_VERSION_MINOR) >= 2)