Hola. See bug 118386; short version is that the deps for gnustep-base-art <0.9.4-r2 haven't been valid for a while due to ungif being screwed with, thus ungif's removal. Unfortunately, missed this ebuild in depscan- thus masking it since the only stable versions available are all dependant on libungif. Would suggest looking to stable 0.9.4-r2
old versions removed, bumped to more recent ones. Thanks.