Keep old version of gloss for GHC 7.8.x.
Keep old version of gloss for GHC 7.8.x.

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