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

Calculating dependencies ...

!!! Problem resolving dependencies for =app-containers/snapd-2.63
 done!
Dependency resolution took 0.83 s (backtrack: 0/20).


!!! The ebuild selected to satisfy "=app-containers/snapd-2.63" has unmet requirements.
- app-containers/snapd-2.63::gentoo USE="forced-devmode -apparmor -gtk -kde (-systemd)"

  The following REQUIRED_USE flag constraints are unsatisfied:
    systemd

  The above constraints are a subset of the following complete expression:
    !forced-devmode? ( apparmor ) systemd