app-backup/snapper: Fix systemd systemunitdir

Closes: https://bugs.gentoo.org/649630
Closes: gentoo#7363

app-backup/snapper/snapper-0.5.4.ebuild

@@ -1,8 +1,10 @@
-# Copyright 1999-2018 Gentoo Foundation
+# Copyright 1999-2017 Gentoo Foundation
 # Distributed under the terms of the GNU General Public License v2
 
 EAPI=6
 
+inherit systemd
+
 DESCRIPTION="Command-line program for btrfs and ext4 snapshot management"
 HOMEPAGE="http://snapper.io/"
 SRC_URI="ftp://ftp.suse.com/pub/projects/snapper/${P}.tar.bz2"
@@ -36,6 +38,14 @@ PATCHES=(
 	"${FILESDIR}"/cron-confd.patch
 )
 
+src_prepare() {
+	default
+
+	sed -e "s,/usr/lib/systemd/system,$(systemd_get_systemunitdir),g" \
+		-i data/Makefile.* \
+		|| die "Failed to fix systemd services and timers installation path"
+}
+
 src_configure() {
 	local myeconfargs=(
 		--with-conf="/etc/conf.d"