Index: sys/conf/kern.post.mk
===================================================================
--- sys/conf/kern.post.mk
+++ sys/conf/kern.post.mk
@@ -63,23 +63,30 @@
 		    ${MAKEOBJDIRPREFIX}${SRC_BASE}/include/osreldate.h
 .endif
 # Keep the related ports builds in the obj directory so that they are only rebuilt once per kernel build
-WRKDIRPREFIX?=	${.OBJDIR}
+WRKDIRPREFIX?=		${.OBJDIR}
+STAGEDSHAREDIR?=	${.OBJDIR}/share.ports
+STAGEDSHAREMK=		${STAGEDSHAREDIR}/mk
 PORTSMODULESENV=\
 	env \
 	-u CC \
 	-u CXX \
 	-u CPP \
-	-u MAKESYSPATH \
-	MAKEFLAGS="${MAKEFLAGS:M*:tW:S/^-m /-m_/g:S/ -m / -m_/g:tw:N-m_*}" \
-	SYSDIR=${SYSDIR} \
+	-u MK_AUTO_OBJ \
+	-u MAKEOBJDIR \
+	MAKESYSPATH=${STAGEDSHAREMK} \
+	MAKEFLAGS="${MAKEFLAGS:M*:tW:S/^-m /-m_/g:S/ -m / -m_/g:tw:N-m_*:NMK_AUTO_OBJ=*}" \
 	PATH=${PATH}:${LOCALBASE}/bin:${LOCALBASE}/sbin \
 	SRC_BASE=${SRC_BASE} \
 	OSVERSION=${OSRELDATE} \
 	WRKDIRPREFIX=${WRKDIRPREFIX}
 
+${STAGEDSHAREMK}:
+	mkdir -p ${.TARGET}
+	${MAKE} BINDIR=${STAGEDSHAREDIR} -C ${SRC_BASE}/share/mk install
+
 # The WRKDIR needs to be cleaned before building, and trying to change the target
 # with a :C pattern below results in install -> instclean
-all:
+all: ${STAGEDSHAREMK}
 .for __i in ${PORTS_MODULES}
 	@${ECHO} "===> Ports module ${__i} (all)"
 	cd $${PORTSDIR:-/usr/ports}/${__i}; ${PORTSMODULESENV} ${MAKE} -B clean build
@@ -87,7 +94,7 @@
 
 .for __target in install reinstall clean
 ${__target}: ports-${__target}
-ports-${__target}:
+ports-${__target}: ${STAGEDSHAREMK}
 .for __i in ${PORTS_MODULES}
 	@${ECHO} "===> Ports module ${__i} (${__target})"
 	cd $${PORTSDIR:-/usr/ports}/${__i}; ${PORTSMODULESENV} ${MAKE} -B ${__target:C/(re)?install/deinstall reinstall/}