Looks like alpha has cups useflag masked? gnome-base/gnome-core-apps/gnome-core-apps-3.8.0.ebuild: RDEPEND: ~alpha(default/linux/alpha/13.0) ['>=gnome-base/gnome-control-center-3.8.0[cups?]']
This was caused by me masking it for the other packages locally but forgetting to commit (I have just noticed it when use masking git USE flag for gedit-plugins) *** This bug has been marked as a duplicate of bug 478078 ***