Index: tauon/toolchain.eclass
===================================================================
--- tauon.orig/toolchain.eclass	2013-07-28 14:27:45.501837905 +0900
+++ tauon/toolchain.eclass	2013-07-28 14:28:08.145950197 +0900
@@ -748,6 +748,20 @@
 			"${S}"/libstdc++-v3/python/Makefile.in || die
 	fi
 
+	# we use our libtool on Darwin
+	sed -i -e "s:/usr/bin/libtool:${EPREFIX}/usr/bin/${CTARGET}-libtool:" \
+		"${S}"/gcc/config/darwin.h || die "sed gcc/config/darwin.h failed"
+	# add prefixed Frameworks to default search paths (may want to change this
+	# in a cross-compile)
+	sed -i -e "/\"\/System\/Library\/Frameworks\"\,/i\ \   \"${EPREFIX}/Frameworks\"\, " \
+		"${S}"/gcc/config/darwin-c.c || die "sed  gcc/config/darwin-c.c failed"
+
+	# for some reason the LD_LIBRARY_PATH (or whatever it is on the used
+	# platform) is set with the target libs in it, that kills the host tools
+	if is_crosscompile ; then
+		sed -i -e 's/@RPATH_ENVVAR@/NO@RPATH_ENVVAR@/g' "${S}"/Makefile.in || die
+	fi
+
 	# make sure the pkg config files install into multilib dirs.
 	# since we configure with just one --libdir, we can't use that
 	# (as gcc itself takes care of building multilibs).  #435728