Created attachment 478094 [details, diff] 0001-Missing-variables-and-minor-adjustments.patch Here is a git format-patch to provide a cleaner version of the ebuild.
https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=7bf2126e619488125db317d7ae6e3271a0493747 (please note the update to commit subject)