Resolving dependencies... cabal: Could not resolve dependencies: trying: UMM-0.3.1 (user goal) trying: base-4.9.0.0/installed-4.9... (dependency of UMM-0.3.1) trying: process-1.4.2.0/installed-1.4... (dependency of UMM-0.3.1) next goal: haskell98 (dependency of UMM-0.3.1) rejecting: haskell98-2.0.0.3 (conflict: base==4.9.0.0/installed-4.9..., haskell98 => base>=4.7 && <4.8) rejecting: haskell98-2.0.0.2 (conflict: base==4.9.0.0/installed-4.9..., haskell98 => base==4.6.*) rejecting: haskell98-2.0.0.1, haskell98-2.0.0.0 (conflict: process => directory==1.2.6.2/installed-1.2..., haskell98 => directory>=1.1 && <1.2) rejecting: haskell98-1.1.0.1, haskell98-1.1.0.0, haskell98-1.0.1.1 (conflict: base==4.9.0.0/installed-4.9..., haskell98 => base>=3 && <4.6) rejecting: haskell98-1.0.1.0 (conflict: base==4.9.0.0/installed-4.9..., haskell98 => base<4.6) rejecting: haskell98-1.0 (conflict: base==4.9.0.0/installed-4.9..., haskell98 => base<4.3) Dependency tree exhaustively searched.