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.
+ 30 Aug 2014; Michał Górny <mgorny@gentoo.org> weex-2.6.1.5-r1.ebuild: + Replace einstall with emake install, bug #521586.