hackage2nix: don't update errors to version 2.x yet
hackage2nix: don't update errors to version 2.x yet

spencerjanssen/cabal2nix,gridaphobe/cabal2nix,jb55/cabal2nix,dmalikov/cabal2nix,psibi/cabal2nix,bennofs/cabal2nix,Fuuzetsu/cabal2nix