Just replace IUSE="" by IUSE="hoogle" in syb-0.4.3.ebuild
Unfortunately the same problem exists with many more packages in dev-haskell.
Yeah, I've done major .eclass update yesterday and didn't test it enough. This should disable hoogle (as it always was) in the main tree: > 02 Jan 2015; Sergei Trofimovich <slyfox@gentoo.org> haskell-cabal.eclass: > Properly disable USE=hoogle. Thanks for the report!
*** Bug 534302 has been marked as a duplicate of this bug. ***
*** Bug 534314 has been marked as a duplicate of this bug. ***
*** Bug 534510 has been marked as a duplicate of this bug. ***