This bug is named wrongly. Sorry. What it was meant to say is that gtk-doc is missing from IUSE in some/all the ebuilds.
ferret, any chance you can provide a list?
/usr/portage/dev-libs/glib/glib-2.2.3.ebuild:IUSE="doc debug" /usr/portage/dev-libs/glib/glib-2.4.0.ebuild:IUSE="doc debug" /usr/portage/dev-libs/glib/glib-2.4.1.ebuild:IUSE="doc" /usr/portage/dev-libs/glib/glib-2.4.2.ebuild:IUSE="doc"
Huh? gtk-doc isn't a USE flag AFAICT
The doc USE flag is being used in all of the examples. Seems invalid to me.