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

Calculating dependencies ... done!
Dependency resolution took 0.99 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-remote-desktop-50.2::gentoo[rdp]
# required by =net-misc/gnome-remote-desktop-50.2 (argument)
>=net-misc/freerdp-3.32.2 server
# required by net-misc/gnome-remote-desktop-50.2::gentoo
# required by =net-misc/gnome-remote-desktop-50.2 (argument)
>=x11-wm/mutter-50.5 screencast

!!! The ebuild selected to satisfy "x11-wm/mutter[screencast]" has unmet requirements.
- x11-wm/mutter-50.5::gentoo USE="(xwayland) -bash-completion -debug -devkit -elogind -gnome -gtk-doc -introspection -screencast (-selinux) -sysprof (-systemd) -test" INPUT_DEVICES="-wacom" VIDEO_CARDS="-nvidia"

  The following REQUIRED_USE flag constraints are unsatisfied:
    exactly-one-of ( elogind systemd )

  The above constraints are a subset of the following complete expression:
    devkit? ( screencast ) gtk-doc? ( introspection ) exactly-one-of ( elogind systemd ) test? ( screencast )

(dependency required by "net-misc/gnome-remote-desktop-50.2::gentoo" [ebuild])
(dependency required by "=net-misc/gnome-remote-desktop-50.2" [argument])