Please add a slot operator to qtbase dependency in kde-frameworks/kcmutils ebuilds. I wanted to downgrade qt from 6.9999 (6.8) to 6.6.2 . /usr/lib64/libexec/kf6/kcmdesktopfilegenerator: /usr/lib64/libQt6Core.so.6: version `Qt_6.8' not found (required by /usr/lib64/libexec/kf6/kcmdesktopfilegenerator)
Library downgrades are generally not supported and that's not what subslots are for. The definition of the subslot for dev-qt/qtbase would be use of private headers .