repoman should complain, when REQUIRED_USE is not satisfiable. this is possible, when USE flags are masked on specific arches. example net-libs/webkit-gtk: REQUIRED_USE="introspection? ( geoloc gstreamer )" USE=geoloc is only unmasked on amd64 and x86. on arm you get # emerge -pv webkit-gtk These are the packages that would be merged, in order: Calculating dependencies - !!! Problem resolving dependencies for net-libs/webkit-gtk ... done! !!! The ebuild selected to satisfy "webkit-gtk" has unmet requirements. - net-libs/webkit-gtk-1.8.1-r301::gentoo USE="gstreamer introspection jit spell test webgl (-aqua) -coverage -debug -doc (-geoloc) (-webkit2)" The following REQUIRED_USE flag constraints are unsatisfied: introspection? ( geoloc ) The above constraints are a subset of the following complete expression: introspection? ( geoloc gstreamer )
repoman support has been removed per bug 835013. Please file a new bug (or, I suppose, reopen this one) if you feel this check is still applicable to pkgcheck and doesn't already exist.
pkgcheck has RequiredUseDefaults.