kde-plasma/plasma-meta-5.5.2 depends on >=kde-plasma/kscreenlocker-5.5.2:5. At the same time kde-apps-meta-15.12.0 has the following dependency graph: (a) kde-apps-meta-15.12.0:5 (b) kde-apps/kdeartwork-meta-15.08.3:5 (c) kde-apps/kdeartwork-kscreensaver-15.08.3:4 (d) kde-base/kscreensaver-4.11.19:4 (e) kde-base/kcheckpass-4.11.19:4 But kde-base/kcheckpass:4 and kde-plasma/kscreenlocker:5 are blocking each other. Hence, at the moment I use KDE Plasma 5.5 and KDE apps 15.12 without KDE artwork. Essentially, I did not merge the kde-apps-meta ebuild but emerged all dependencies individually except the artwork-meta package.
You didn't post the blocker message, however kde-base/kcheckpass-4.11.22-r1 would be the solution.
Yes, indeed it is. Thank you! I do not know if is worth to be posted as a bug report and if I should open a new bug report but this problems is another one on top of a list of packages that needs to be unmasked via the keyword "~amd64" in order to merge KDE Plasma 5.5, KDE Framework 5.17 and KDE Apps 5.12 successfully. In the KDE overlay there are already the files (a) "kde-frameworks-5.17.keyword" (b) "kde-plasma-5.5.keywords" that needs to be symlinked into "/etc/portage/package.accept_keywords". Unfortunately, these both files only unmasks the required packages in "kde-plasma/*" and "kde-frameworks/*" respectively. But there are some auxiliary packages that needs to be unmasked. At the moment for my environment this list of packages is <app-crypt/qca-2.2.0 ~amd64 =dev-cpp/eigen-3.2.5 ~amd64 <dev-libs/libappindicator-12.10.1 ~amd64 =dev-libs/libdbusmenu-12.10.2-r2 ~amd64 <dev-libs/libindicator-12.10.2 ~amd64 =dev-qt/qtimageformats-5.5.1 ~amd64 =dev-qt/qtpaths-5.4.2 ~amd64 =media-libs/qt-gstreamer-1.2.0-r1 ~amd64 =net-libs/telepathy-accounts-signon-1.0 ~amd64 =net-libs/telepathy-logger-qt-15.04.0 ~amd64 =x11-misc/sddm-0.11.0-r1 ~amd64 =x11-misc/xdg-utils-1.1.0_rc3_p20150825 ~amd64 kde-base/kcheckpass:4 ~amd64 On this list the last entry was just freshly added. Perhaps it would be nice to have a third file "kde-auxilary.keywords" (or similar) that collects all the packages that needs to be unmasked, too, but are not directly in the KDE tree.
Well, some manual work is always to be expected by someone mixing amd64 with ~amd64 packages. The package.keywords files are only helpers for the kde packages there.
Ok. I mark the report as "resolved" and "invalid".