Install this version:
emerge -a =dev-haskell/either-5.0.3
If this version is masked, you can unmask it using the autounmask tool or standard emerge options:
autounmask =dev-haskell/either-5.0.3
Or alternatively:
emerge --autounmask-write -a =dev-haskell/either-5.0.3
# Copyright 1999-2026 Gentoo Authors
# Distributed under the terms of the GNU General Public License v2
EAPI=8
CABAL_HACKAGE_REVISION=2
CABAL_FEATURES="lib profile haddock hoogle hscolour test-suite"
inherit haskell-cabal
DESCRIPTION="An either monad transformer"
HOMEPAGE="https://github.com/ekmett/either"
LICENSE="BSD"
SLOT="0/${PV}"
KEYWORDS="~amd64 ~x86"
RDEPEND="dev-haskell/bifunctors:=[profile?]
dev-haskell/profunctors:=[profile?]
dev-haskell/semigroupoids:=[profile?]
dev-lang/ghc:="
DEPEND="${RDEPEND}"
BDEPEND="dev-haskell/cabal:=
test? ( dev-haskell/tasty
dev-haskell/tasty-quickcheck
dev-haskell/quickcheck )"
src_prepare() {
haskell-cabal_src_prepare
sed -i '/license-file/d' either.cabal || die "sed failed"
}
dev-haskell/bifunctors:=[profile?] dev-haskell/profunctors:=[profile?] dev-haskell/semigroupoids:=[profile?] dev-lang/ghc:=
dev-haskell/bifunctors:=[profile?] dev-haskell/profunctors:=[profile?] dev-haskell/semigroupoids:=[profile?] dev-lang/ghc:=
dev-haskell/cabal:= test? ( dev-haskell/tasty dev-haskell/tasty-quickcheck dev-haskell/quickcheck )