app-accessibility/epos: use and depend on byacc (fixes bug #513760)

use and depend on byacc due to problems with =sys-devel/bison-3*,
fixes bug #513760.

Acked-By: William Hubbs <williamh@gentoo.org>

Package-Manager: Portage-2.3.5, Repoman-2.3.1

app-accessibility/epos/epos-2.5.37-r2.ebuild

@@ -1,4 +1,4 @@
-# Copyright 1999-2016 Gentoo Foundation
+# Copyright 1999-2017 Gentoo Foundation
 # Distributed under the terms of the GNU General Public License v2
 
 EAPI=5
@@ -14,7 +14,8 @@ SLOT="0"
 KEYWORDS="alpha amd64 hppa ia64 ppc ppc64 x86"
 IUSE=""
 
-DEPEND=">=app-text/sgmltools-lite-3.0.3-r9"
+DEPEND=">=app-text/sgmltools-lite-3.0.3-r9
+	dev-util/byacc"
 RDEPEND=""
 
 src_prepare() {
@@ -31,7 +32,8 @@ src_prepare() {
 src_configure() {
 	econf \
 		--enable-charsets \
-		--disable-portaudio
+		--disable-portaudio \
+		YACC=byacc
 }
 
 src_install() {