--- old/make/autoconf/spec.gmk.in	2019-04-04 15:11:56.009658098 -0700
+++ new/make/autoconf/spec.gmk.in	2019-04-04 15:11:55.389636919 -0700
@@ -138,7 +138,9 @@
 
 # The top-level directory of the source repository
 TOPDIR:=@TOPDIR@
-
+# Usually the top level directory, but could be something else if a custom
+# root is defined.
+WORKSPACE_ROOT:=@WORKSPACE_ROOT@
 
 IMPORT_MODULES_CLASSES:=@IMPORT_MODULES_CLASSES@
 IMPORT_MODULES_CMDS:=@IMPORT_MODULES_CMDS@