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

Calculating dependencies ...

!!! Problem resolving dependencies for =www-client/uget-2.2.3
 done!
Dependency resolution took 0.83 s (backtrack: 0/20).


!!! The ebuild selected to satisfy "=www-client/uget-2.2.3" has unmet requirements.
- www-client/uget-2.2.3::gentoo USE="gnutls nls openssl -appindicator -aria2 -control-socket -gstreamer -libnotify -rss"

  The following REQUIRED_USE flag constraints are unsatisfied:
    exactly-one-of ( gnutls openssl )