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

Calculating dependencies ... done!
Dependency resolution took 1.48 s (backtrack: 0/20).


The following USE changes are necessary to proceed:
 (see "package.use" in the portage(5) man page for more details)
# required by x11-misc/xdg-utils-1.2.1-r11::gentoo
# required by kde-frameworks/kf-env-6::gentoo
# required by kde-plasma/libplasma-6.8.0::gentoo
# required by dev-libs/kirigami-addons-1.15.0::gentoo
# required by media-sound/kasts-26.08.2::gentoo
# required by =media-sound/kasts-26.08.2 (argument)
>=app-text/xmlto-0.0.28-r11 text
# required by kde-plasma/libplasma-6.8.0::gentoo
# required by dev-libs/kirigami-addons-1.15.0::gentoo
# required by media-sound/kasts-26.08.2::gentoo
# required by =media-sound/kasts-26.08.2 (argument)
>=dev-qt/qtbase-6.11.2-r2 icu wayland
# required by dev-libs/kirigami-addons-1.15.0::gentoo
# required by media-sound/kasts-26.08.2::gentoo
# required by =media-sound/kasts-26.08.2 (argument)
>=dev-qt/qtmultimedia-6.11.2 qml
# required by kde-plasma/libplasma-6.8.0::gentoo
# required by dev-libs/kirigami-addons-1.15.0::gentoo
# required by media-sound/kasts-26.08.2::gentoo
# required by =media-sound/kasts-26.08.2 (argument)
>=dev-qt/qt5compat-6.11.2 qml icu
# required by kde-plasma/libplasma-6.8.0::gentoo
# required by dev-libs/kirigami-addons-1.15.0::gentoo
# required by media-sound/kasts-26.08.2::gentoo
# required by =media-sound/kasts-26.08.2 (argument)
>=kde-frameworks/kconfig-6.31.0 qml

 * In order to avoid wasting time, backtracking has terminated early
 * due to the above autounmask change(s). The --autounmask-backtrack=y
 * option can be used to force further backtracking, but there is no
 * guarantee that it will produce a solution.