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

Calculating dependencies ...

!!! Problem resolving dependencies for =app-misc/radeontop-1.4
 done!
Dependency resolution took 0.85 s (backtrack: 0/20).


!!! The ebuild selected to satisfy "=app-misc/radeontop-1.4" has unmet requirements.
- app-misc/radeontop-1.4::gentoo USE="nls" VIDEO_CARDS="-amdgpu -radeon"

  The following REQUIRED_USE flag constraints are unsatisfied:
    any-of ( video_cards_amdgpu video_cards_radeon )