Resolving dependencies... Configuring base-orphans-0.5.4... Configuring cabal-doctest-1... Building base-orphans-0.5.4... Building cabal-doctest-1... Installed base-orphans-0.5.4 Configuring mtl-2.2.1... Building mtl-2.2.1... Configuring prelude-extras-0.4.0.3... Installed cabal-doctest-1 Building prelude-extras-0.4.0.3... Configuring stm-2.4.4.1... Installed mtl-2.2.1 Building stm-2.4.4.1... Configuring semigroups-0.18.2... Installed prelude-extras-0.4.0.3 Building semigroups-0.18.2... Configuring transformers-compat-0.5.1.4... Installed semigroups-0.18.2 Configuring text-1.2.2.1... Installed stm-2.4.4.1 Building transformers-compat-0.5.1.4... Building text-1.2.2.1... Installed transformers-compat-0.5.1.4 Configuring list-transformer-1.0.1... Building list-transformer-1.0.1... Installed list-transformer-1.0.1 Configuring StateVar-1.1.0.4... Building StateVar-1.1.0.4... Configuring exceptions-0.8.3... Installed StateVar-1.1.0.4 Building exceptions-0.8.3... Configuring tagged-0.8.5... Installed exceptions-0.8.3 Building tagged-0.8.5... Configuring mmorph-1.0.9... Installed tagged-0.8.5 Building mmorph-1.0.9... Configuring distributive-0.5.2... Installed text-1.2.2.1 Installed mmorph-1.0.9 Configuring hashable-1.2.5.0... Building hashable-1.2.5.0... Building distributive-0.5.2... Installed hashable-1.2.5.0 Configuring void-0.7.1... Installed distributive-0.5.2 Building void-0.7.1... Installed void-0.7.1 Configuring contravariant-1.4... Building contravariant-1.4... Installed contravariant-1.4 Configuring comonad-5... Building comonad-5... Installed comonad-5 Configuring bifunctors-5.4.1... Building bifunctors-5.4.1... Installed bifunctors-5.4.1 Configuring profunctors-5.2... Configuring semigroupoids-5.1... Building profunctors-5.2... Building semigroupoids-5.1... Installed profunctors-5.2 Installed semigroupoids-5.1 Configuring free-4.12.4... Building free-4.12.4... Installed free-4.12.4 Configuring transformers-eff-0.2.0.0... Building transformers-eff-0.2.0.0... Failed to install transformers-eff-0.2.0.0 Build log ( /home/builder/.cabal/logs/transformers-eff-0.2.0.0.log ): cabal: Entering directory '/tmp/cabal-tmp-13529/transformers-eff-0.2.0.0' Configuring transformers-eff-0.2.0.0... Building transformers-eff-0.2.0.0... Preprocessing library transformers-eff-0.2.0.0... [1 of 7] Compiling Control.Effect ( Control/Effect.hs, dist/build/Control/Effect.o ) Control/Effect.hs:18:1: warning: [-Wunused-imports] The import of ‘Control.Monad.Morph’ is redundant except perhaps to import instances from ‘Control.Monad.Morph’ To import instances alone, use: import Control.Monad.Morph() Control/Effect.hs:54:17: warning: [-Wname-shadowing] This binding for ‘sum’ shadows the existing binding imported from ‘Prelude’ at Control/Effect.hs:12:8-21 (and originally defined in ‘Data.Foldable’) [2 of 7] Compiling Control.Effect.Environment ( Control/Effect/Environment.hs, dist/build/Control/Effect/Environment.o ) [3 of 7] Compiling Control.Effect.Exception ( Control/Effect/Exception.hs, dist/build/Control/Effect/Exception.o ) [4 of 7] Compiling Control.Effect.IO ( Control/Effect/IO.hs, dist/build/Control/Effect/IO.o ) [5 of 7] Compiling Control.Effect.Identity ( Control/Effect/Identity.hs, dist/build/Control/Effect/Identity.o ) [6 of 7] Compiling Control.Effect.Nondeterminism ( Control/Effect/Nondeterminism.hs, dist/build/Control/Effect/Nondeterminism.o ) Control/Effect/Nondeterminism.hs:38:9: error: • Could not deduce (Foldable f0) arising from a use of ‘choose’ from the context: Nondeterministic m bound by the type signature for: mzero :: Nondeterministic m => m a at Control/Effect/Nondeterminism.hs:37:1-34 The type variable ‘f0’ is ambiguous These potential instances exist: instance Foldable (Either a) -- Defined in ‘Data.Foldable’ instance Foldable Maybe -- Defined in ‘Data.Foldable’ instance Foldable ((,) a) -- Defined in ‘Data.Foldable’ ...plus one other ...plus 40 instances involving out-of-scope types (use -fprint-potential-instances to see them all) • In the expression: choose mempty In an equation for ‘mzero’: mzero = choose mempty Control/Effect/Nondeterminism.hs:38:16: error: • Could not deduce (Monoid (f0 a)) arising from a use of ‘mempty’ from the context: Nondeterministic m bound by the type signature for: mzero :: Nondeterministic m => m a at Control/Effect/Nondeterminism.hs:37:1-34 The type variable ‘f0’ is ambiguous Relevant bindings include mzero :: m a (bound at Control/Effect/Nondeterminism.hs:38:1) These potential instances exist: instance Monoid a => Monoid (IO a) -- Defined in ‘GHC.Base’ instance Monoid a => Monoid (Maybe a) -- Defined in ‘GHC.Base’ instance Monoid b => Monoid (a -> b) -- Defined in ‘GHC.Base’ ...plus five others ...plus 17 instances involving out-of-scope types (use -fprint-potential-instances to see them all) • In the first argument of ‘choose’, namely ‘mempty’ In the expression: choose mempty In an equation for ‘mzero’: mzero = choose mempty cabal: Leaving directory '/tmp/cabal-tmp-13529/transformers-eff-0.2.0.0' cabal: Error: some packages failed to install: transformers-eff-0.2.0.0 failed during the building phase. The exception was: ExitFailure 1