Your package is runtime-depending on dev-util/gtk-doc standing to
http://tinderbox.dev.gentoo.org/misc/rindex/dev-util/gtk-doc . dev-util/gtk-doc
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.
Thanks,
Diego