--- valgrind-3.7.0-r3.ebuild.orig	2012-02-17 03:02:54.000000000 +0100
+++ valgrind-3.7.0-r3.ebuild	2012-03-23 20:29:51.000000000 +0100
@@ -21,6 +21,10 @@
 	# Correct hard coded doc location
 	sed -i -e "s:doc/valgrind:doc/${PF}:" docs/Makefile.am || die
 
+	# Don't force multiarch stuff on OSX
+	sed -i -e 's:-arch \(i386\|x86_64\)::g' \
+		Makefile.all.am || die
+
 	# Respect CFLAGS, LDFLAGS
 	epatch "${FILESDIR}"/${PN}-3.7.0-respect-flags.patch
 
@@ -68,6 +72,9 @@
 		! has_multilib_profile && myconf="${myconf} --enable-only64bit"
 	fi
 
+	use x86-macos && myconf="${myconf} --enable-only32bit"
+	use x64-macos && myconf="${myconf} --enable-only64bit"
+
 	# Don't use mpicc unless the user asked for it (bug #258832)
 	if ! use mpi; then
 		myconf="${myconf} --without-mpicc"
@@ -80,7 +87,16 @@
 	emake DESTDIR="${D}" install
 	dodoc AUTHORS FAQ.txt NEWS README*
 
-	pax-mark m "${D}"/usr/$(get_libdir)/valgrind/*-*-linux
+	pax-mark m "${ED}"/usr/$(get_libdir)/valgrind/*-*-linux
+
+	if [[ ${CHOST} == *-darwin* ]] ; then
+		# fix install_names on shared libraries, can't turn them into bundles,
+		# as dyld won't load them any more then
+		local l
+		for l in "${ED}"/usr/lib/valgrind/*.so ; do
+			install_name_tool -id "${EPREFIX}"/usr/lib/valgrind/${l##*/} "${l}"
+		done
+	fi
 }
 
 pkg_postinst() {