Resolving dependencies... cabal: Could not resolve dependencies: next goal: haskelldb (user goal) rejecting: haskelldb-2.2.4, 2.2.2, 2.2.1, 2.1.1, 2.1.0, 2.0.1.1, 2.0.1 (global constraint requires ==2.0) trying: haskelldb-2.0 trying: base-4.8.1.0/installed-4f7... (dependency of haskelldb-2.0) next goal: mtl (dependency of haskelldb-2.0) rejecting: mtl-2.2.1, 2.2.0.1, 2.2, 2.1.3.1, 2.1.2, 2.1.1, 2.1, 2.0.1.1, 2.0.1.0, 2.0.0.0 (conflict: haskelldb => mtl>=1.1 && <2) rejecting: mtl-1.1.1.1, 1.1.1.0 (conflict: base==4.8.1.0/installed-4f7..., mtl => base<4.6) rejecting: mtl-1.1.0.2, 1.1.0.1, 1.1.0.0 (conflict: base==4.8.1.0/installed-4f7..., mtl => base<4.3) rejecting: mtl-1.0 (conflict: haskelldb => mtl>=1.1 && <2) Dependency tree exhaustively searched.