emerge -auDN @world gives the following messages:
!!! The following update has been skipped due to unsatisfied dependencies: lxde-base/lxsession:0 emerge: there are no ebuilds to satisfy "dev-libs/libgee:0". (dependency required by "lxde-base/lxsession-0.4.9.2-r3" [ebuild]
'emerge -s libgee lxsession' shows libgee and lxsession, but not libgee:0 or lxsession:0.