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 7cd35418c6930fd640b71b0a19c87a757519eeb0 Author: David Seifert <soap@gentoo.org> Date: Thu Jan 21 18:49:49 2016 +0100 sci-biology/gmap: Version bump to 2015.12.31.5 Gentoo-Bug: 521640 * Remove use of 'einstall' * EAPI=6