Please check whether the use of 'einstall' in this ebuild is actually needed. From a quick glance at the Makefile, it seems to have proper support for DESTDIR. Therefore, if possible please replace the call to 'einstall' with proper 'default' or 'emake DESTDIR="${D}" install'. Thanks.
commit ac414834093c3bfb137d7155a869650ea32d71ca Author: David Seifert <soap@gentoo.org> Date: Thu Jan 21 09:39:45 2016 +0100 sci-biology/newick-utils: Version bump to 1.6 Gentoo-Bug: 521644 * Remove use of 'einstall' * EAPI=6