Your package is runtime-depending on app-doc/doxygen standing to http://tinderbox.dev.gentoo.org/misc/rindex/app-doc/doxygen . app-doc/doxygen is a tool used almost always at build-time, (it's either a build system or a generator - sorry this is a generic template I start with so I can't tell you right away which one). This means that it should only be depended at build-time.
Please correct your ebuild or document why it is used as a runtime-dependency so that it will not be suspected again.
Fixed in latest...