"app-emulation/wine:0" is blocking app-emulation/wine-staging (app-emulation/wine-2.3:0/0::gentoo, ebuild scheduled for merge) pulled in by app-emulation/wine required by (app-emulation/winetricks-20170614:0/0::gentoo, ebuild scheduled for merge) Should winetricks depend on app-emulation/wine-any?
Just emerge: virtual/wine for the new Gentoo multislot packages.
Portage did not merge virtual/wine because it was masked. I unmasked it and now all is fine.