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

Calculating dependencies ... done!
Dependency resolution took 0.94 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 media-sound/gnome-music-50.0::gentoo
# required by =media-sound/gnome-music-50.0 (argument)
>=gui-libs/gtk-4.22.5-r1 introspection
# required by media-sound/gnome-music-50.0::gentoo
# required by =media-sound/gnome-music-50.0 (argument)
>=gui-libs/libadwaita-1.9.4 introspection
# required by media-sound/gnome-music-50.0::gentoo
# required by =media-sound/gnome-music-50.0 (argument)
>=media-libs/libmediaart-1.9.7 introspection

!!! The ebuild selected to satisfy ">=media-libs/libmediaart-1.9.1:2.0[introspection]" has unmet requirements.
- media-libs/libmediaart-1.9.7::gentoo USE="-gtk -gtk-doc -introspection -qt6 -test -vala"

  The following REQUIRED_USE flag constraints are unsatisfied:
    exactly-one-of ( gtk qt6 )

  The above constraints are a subset of the following complete expression:
    exactly-one-of ( gtk qt6 ) vala? ( introspection )

(dependency required by "media-sound/gnome-music-50.0::gentoo" [ebuild])
(dependency required by "=media-sound/gnome-music-50.0" [argument])