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

Calculating dependencies ... done!
Dependency resolution took 0.88 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 net-misc/gnome-connections-49.0::gentoo
# required by =net-misc/gnome-connections-49.0 (argument)
>=x11-libs/gtk+-3.24.52 introspection
# required by net-misc/gnome-connections-49.0::gentoo
# required by =net-misc/gnome-connections-49.0 (argument)
>=net-libs/gtk-vnc-1.5.0 vala pulseaudio

!!! The ebuild selected to satisfy ">=net-libs/gtk-vnc-0.4.4[pulseaudio,vala]" has unmet requirements.
- net-libs/gtk-vnc-1.5.0::gentoo USE="X -gtk-doc -introspection -pulseaudio -sasl -vala -valgrind -wayland"

  The following REQUIRED_USE flag constraints are unsatisfied:
    vala? ( introspection )

(dependency required by "net-misc/gnome-connections-49.0::gentoo" [ebuild])
(dependency required by "=net-misc/gnome-connections-49.0" [argument])