Created attachment 478238 [details]
Calibre 3.0 introduced a new dependency on a pypi unrardll (see https://bugs.gentoo.org/show_bug.cgi?id=622854 and https://github.com/kovidgoyal/build-calibre/blob/master/scripts/sources.json).
The attached ebuild adds in the dependency.
this is still missing in the latest Gentoo release of Calibre (3.8.0). For people who use Calibre to track comics and Manga, this is an important feature.