Index: Mk/bsd.port.mk
===================================================================
--- Mk/bsd.port.mk
+++ Mk/bsd.port.mk
@@ -859,6 +859,10 @@
 #				- The substitution process is the same as PLIST_FILES, as
 #				  described below except that any line beginning with @comment
 #				  is deleted.
+# SUB_FILES_EARLY
+#				- Like SUB_FILES except that substitution occurs in the
+#				  extract target allowing the files to be used in configure
+#				  and build targets.
 # SUB_LIST		- List of "variable=value" pair for substitution in ${SUB_FILES}
 #				  Some pairs are added by default: eg. PREFIX=${PREFIX}
 #
@@ -4531,6 +4535,19 @@
 .endif
 .endif
 
+.if !target(apply-slist-early)
+apply-slist-early:
+.if defined(SUB_FILES_EARLY)
+.for file in ${SUB_FILES_EARLY}
+.if !exists(${FILESDIR}/${file}.in)
+	@${ECHO_MSG} "** Missing ${FILESDIR}/${file}.in for ${PKGNAME}."; exit 1
+.else
+	@${SED} ${_SUB_LIST_TEMP} -e '/^@comment /d' ${FILESDIR}/${file}.in > ${WRKDIR}/${file}
+.endif
+.endfor
+.endif
+.endif
+
 # Generate packing list.  Also tests to make sure all required package
 # files exist.
 
@@ -5304,6 +5321,7 @@
 _CONFIGURE_SEQ=	150:build-depends 151:lib-depends 160:create-binary-alias \
 				161:create-binary-wrappers \
 				200:configure-message \
+				250:apply-slist-early \
 				300:pre-configure 450:pre-configure-script \
 				490:run-autotools-fixup 500:do-configure 700:post-configure \
 				850:post-configure-script \