Resolving dependencies... Configuring util-0.1.10.0... Configuring reflection-2.1.3... Building reflection-2.1.3... Building util-0.1.10.0... Failed to install util-0.1.10.0 Build log ( /home/builder/.cabal/logs/ghc-8.2.2/util-0.1.10.0-2sAi33bJKVZ1SmmumOGo87.log ): cabal: Entering directory '/tmp/cabal-tmp-888/util-0.1.10.0' Configuring util-0.1.10.0... Preprocessing library for util-0.1.10.0.. Building library for util-0.1.10.0.. [1 of 2] Compiling Util ( Util.hs, dist/build/Util.o ) Util.hs:152:28: error: • Could not deduce (Semigroup b) arising from a use of ‘<>’ from the context: (Applicative p, Monoid b, Foldable f) bound by the type signature for: foldMapA :: forall (p :: * -> *) b (f :: * -> *) a. (Applicative p, Monoid b, Foldable f) => (a -> p b) -> f a -> p b at Util.hs:151:1-77 Possible fix: add (Semigroup b) to the context of the type signature for: foldMapA :: forall (p :: * -> *) b (f :: * -> *) a. (Applicative p, Monoid b, Foldable f) => (a -> p b) -> f a -> p b • In the first argument of ‘liftA2’, namely ‘(<>)’ In the first argument of ‘(.)’, namely ‘liftA2 (<>)’ In the first argument of ‘foldr’, namely ‘(liftA2 (<>) . f)’ | 152 | foldMapA f = foldr (liftA2 (<>) . f) (pure mempty) | ^^^^ cabal: Leaving directory '/tmp/cabal-tmp-888/util-0.1.10.0' Installed reflection-2.1.3 cabal: Error: some packages failed to install: alg-0.2.4.0-H2RsRY8kSkc5aJTtf9t7X4 depends on alg-0.2.4.0 which failed to install. category-0.2.0.1-35iyfpPVOG9FEduXXqCjFR depends on category-0.2.0.1 which failed to install. constraint-0.1.1.1-18IMV1aILDk6bymIuDoBGN depends on constraint-0.1.1.1 which failed to install. constraint-reflection-0.1.0.0-4O0MWe2mqPTGlvs7DiRMFm depends on constraint-reflection-0.1.0.0 which failed to install. util-0.1.10.0-2sAi33bJKVZ1SmmumOGo87 failed during the building phase. The exception was: ExitFailure 1