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="${D}" install'. Thanks.
Created attachment 412224 [details, diff] guile-1.8.8-sandbox.patch emake DESTDIR="${D}" install causes a sandbox violation due to it trying to rm /usr/bin/build-guile.
Fixed in 1.8.8-r2.