Hi! app-arch/unrar doesn't compile on cross-compilation between two different arches, because the compiler is simply 'g++', and not '${CHOST}-g++'. To fix it, is only needed to specify CXX variable when emake is executed, like the CXXFLAGS in this ebuild. With the attached patch works to me well between i686, ppc and amd64. Good bye!
Created attachment 86095 [details, diff] unrar-3.4.3.ebuild.patch
added to cvs, thanks !