We can't use ${WORLDTMP}/usr/{include,lib} for the compat layer. This

is because we populate these directories later, and a subsequent
-DNOCLEAN build may fail.  So, we put them in
${WORLDTMP}/build/usr/{include,lib} instead and adjust Makefile.boot.

Again, this works on -stable and -current, but might break older
versions.

Submitted by: ru@

Makefile.inc1

@@ -159,6 +159,9 @@ INSTALLTMP!=	/usr/bin/mktemp -d -u -t install
 #
 # Building a world goes through the following stages
 #
+# 1. libbuild stage [BMAKE]
+#	This stage is responsible for creating compatibility shims that are
+#	needed by the bootstrap-tool, build-tool and cross-tool stages.
 # 1. bootstrap-tool stage [BMAKE]
 #	This stage is responsible for creating programs that
 #	are needed for backward compatibility reasons. They
@@ -276,6 +279,15 @@ _worldtmp:
 	mkdir -p ${WORLDTMP}/usr/include/${_dir}
 .endfor
 	ln -sf ${.CURDIR}/sys ${WORLDTMP}
+.for _dir in lib include include/sys
+	mkdir -p ${WORLDTMP}/build/usr/${_dir}
+.endfor
+_libbuild:
+	@echo
+	@echo "--------------------------------------------------------------"
+	@echo ">>> stage 1: libbuild"
+	@echo "--------------------------------------------------------------"
+	cd ${.CURDIR}; ${BMAKE} libbuild
 _bootstrap-tools:
 	@echo
 	@echo "--------------------------------------------------------------"
@@ -336,7 +348,7 @@ everything:
 
 WMAKE_TGTS=
 .if !defined(SUBDIR_OVERRIDE)
-WMAKE_TGTS+=	_worldtmp _bootstrap-tools
+WMAKE_TGTS+=	_worldtmp _libbuild _bootstrap-tools
 .endif
 WMAKE_TGTS+=	_cleanobj _obj _build-tools
 .if !defined(SUBDIR_OVERRIDE)
@@ -610,8 +622,18 @@ installmost:
 _strfile=	games/fortune/strfile
 .endif
 
+libbuild:
+.for _tool in tools/build
+	@${ECHODIR} "===> ${_tool}"; \
+	    cd ${.CURDIR}/${_tool}; \
+	    ${MAKE} DIRPRFX=${_tool}/ obj; \
+	    ${MAKE} DIRPRFX=${_tool}/ depend; \
+	    ${MAKE} DIRPRFX=${_tool}/ all; \
+	    ${MAKE} DIRPRFX=${_tool}/ DESTDIR=${MAKEOBJDIRPREFIX}/build install
+.endfor
+
 bootstrap-tools:
-.for _tool in tools/build ${_strfile} usr.bin/yacc usr.bin/colldef \
+.for _tool in ${_strfile} usr.bin/yacc usr.bin/colldef \
     usr.bin/makewhatis usr.bin/rpcgen usr.bin/uudecode \
     usr.bin/xargs usr.bin/xinstall \
     usr.sbin/config usr.sbin/kbdcontrol \

tools/build/Makefile.boot

@@ -1,16 +1,18 @@
 # $FreeBSD$
 
 # FreeBSD didn't always have the __FBSDID() macro in <sys/cdefs.h>.
+# We could do this with a sys/cdefs.h wrapper, but given that this would
+# slow down all new builds for such a simple concept, we do it here.
 .if defined(BOOTSTRAPPING) && \
     ( ${BOOTSTRAPPING} < 440001 || \
     ( ${BOOTSTRAPPING} >= 500000 && ${BOOTSTRAPPING} < 500024 ))
 CFLAGS+=	-D__FBSDID=__RCSID
 .endif
 
-CFLAGS+=	-I${WORLDTMP}/usr/include
+CFLAGS+=	-I${WORLDTMP}/build/usr/include
-DPADD=		${WORLDTMP}/usr/lib/libbuild.a
+DPADD=		${WORLDTMP}/build/usr/lib/libbuild.a
 LDADD=		-lbuild
-LDFLAGS=	-L${WORLDTMP}/usr/lib
+LDFLAGS=	-L${WORLDTMP}/build/usr/lib
 
 OLD_MAKE_CONF?=	/etc/make.conf
 .if exists(${OLD_MAKE_CONF})