I copied /usr/portage/app-misc/booh/booh-0.8.5.ebuild to /usr/local/portage/app-misc/booh/booh-0.8.5.ebuild added a ~amd64 keyword unmasked these packages: +dev-ruby/ruby-gettext ~amd64 +dev-ruby/racc ~amd64 +app-misc/booh ~amd64 and booh installed without problems It also runs without problems so far. Please add the ~amd64 keyword to the official ebuild.
0.8.5 Works for me - created 2 galleries - rotated pics, adjusted contrast. Load/Save... it get's a ~amd64 from me - thanks for the report. (Aside: 0.8.6 didn't work - complaining about the Ruby version - or I'd have marked that...)