The 10.1 and 10.2 versions of sys-block/tw_cli use zip archives and don't have DEPEND="app-arch/unzip".
+ 11 Jan 2011; Justin Lecher <jlec@gentoo.org> tw_cli-10.1.ebuild, + tw_cli-10.2.ebuild: + Added DEPEND on app-arch/unzip, #351349 +