Index: ncurses-5.9-r3.ebuild
===================================================================
RCS file: /var/cvsroot/gentoo-x86/sys-libs/ncurses/ncurses-5.9-r3.ebuild,v
retrieving revision 1.17
diff -u -B -r1.17 ncurses-5.9-r3.ebuild
--- ncurses-5.9-r3.ebuild	5 Aug 2014 16:09:26 -0000	1.17
+++ ncurses-5.9-r3.ebuild	2 Dec 2014 19:37:26 -0000
@@ -222,3 +222,15 @@
 	dodoc ANNOUNCE MANIFEST NEWS README* TO-DO doc/*.doc
 	use doc && dohtml -r doc/html/
 }
+
+pkg_preinst() {
+	has_version 'sys-libs/ncurses[tinfo]' &&
+		export had_tinfo=true ||
+		export had_tinfo=false
+}
+
+pkg_postinst() {
+	if $had_tinfo && ! use tinfo ; then
+		# ewarn about running revdep-rebuild
+	fi
+}