The ebuild currently has LICENSE="as-is" which most likely is wrong. - No license is included in the package's zipball. - HOMEPAGE is dead (and it's not archived on archive.org either) Can you please ask upstream for clarification under with terms this package can be distributed?
Mail to upstream sent.
No answer from Gena Obukhov yet. The Tomtree part is free for non-commercial use. I've received a message from Tom Aust confirming that our "free-noncomm" license label would be o.k. for it.
Created attachment 375686 [details] Reply from Gennady Obukhov I've received a reply from Gennady Obukhov, posted here with his permission. We can therefore go for "free-noncomm" here.
+ 25 Apr 2014; Ulrich Müller <ulm@gentoo.org> povtree-1.5.ebuild, + povtree-1.5-r1.ebuild: + Fix LICENSE: Free for non-commercial use, as per e-mail from Tom Aust and + Gennady Obukhov, bug 446168. +
Created attachment 598154 [details] Reply from Tom Aust For completeness, attaching the reply from Tom Aust as well.