emerge -uDva @world

These are the packages that would be merged, in order:

Calculating dependencies \
Invalid ebuild name: /var/git/meta-repo/kits/media-kit/media-gfx/digikam/digikam-8.0.0-beta1.ebuild
... done!

emerge: there are no ebuilds built with USE flags to satisfy "dev-libs/boost[threads]".
!!! One of the following packages is required to complete your request:
- dev-libs/boost-1.78.0-r2::core-kit (Missing IUSE: threads)
(dependency required by "media-gfx/digikam-7.1.0-r1::kde-kit" [ebuild])
(dependency required by "@selected" [set])
(dependency required by "@world" [argument])