Resolving dependencies... Configuring Boolean-0.2.3... Configuring NumInstances-1.4... Building Boolean-0.2.3... Building NumInstances-1.4... Installed Boolean-0.2.3 Configuring applicative-numbers-0.1.3... Building applicative-numbers-0.1.3... Configuring base-orphans-0.5.4... Installed NumInstances-1.4 Building base-orphans-0.5.4... Configuring dlist-0.8.0.2... Installed applicative-numbers-0.1.3 Configuring data-default-class-0.1.2.0... Installed base-orphans-0.5.4 Building dlist-0.8.0.2... Building data-default-class-0.1.2.0... Configuring nats-1.1.1... Installed data-default-class-0.1.2.0 Building nats-1.1.1... Configuring newtype-0.2... Installed dlist-0.8.0.2 Configuring newtype-generics-0.5... Installed nats-1.1.1 Building newtype-0.2... Building newtype-generics-0.5... Configuring mtl-2.2.1... Installed newtype-0.2 Configuring old-locale-1.0.0.7... Installed newtype-generics-0.5 Building mtl-2.2.1... Building old-locale-1.0.0.7... Configuring primitive-0.6.2.0... Installed old-locale-1.0.0.7 Building primitive-0.6.2.0... Configuring reverse-apply-2.0.1... Installed mtl-2.2.1 Building reverse-apply-2.0.1... Configuring random-1.1... Installed reverse-apply-2.0.1 Building random-1.1... Configuring stm-2.4.4.1... Installed primitive-0.6.2.0 Configuring semigroups-0.18.2... Installed random-1.1 Building stm-2.4.4.1... Building semigroups-0.18.2... Configuring transformers-compat-0.5.1.4... Installed semigroups-0.18.2 Building transformers-compat-0.5.1.4... Configuring text-1.2.2.1... Installed stm-2.4.4.1 Building text-1.2.2.1... Configuring ty-0.1.7... Installed transformers-compat-0.5.1.4 Building ty-0.1.7... Installed ty-0.1.7 Configuring data-default-instances-containers-0.0.1... Building data-default-instances-containers-0.0.1... Configuring data-default-instances-dlist-0.0.1... Installed data-default-instances-containers-0.0.1 Building data-default-instances-dlist-0.0.1... Configuring MemoTrie-0.6.7... Installed data-default-instances-dlist-0.0.1 Building MemoTrie-0.6.7... Configuring data-default-instances-old-locale-0.0.1... Installed MemoTrie-0.6.7 Building data-default-instances-old-locale-0.0.1... Configuring music-dynamics-literal-1.9.0... Installed data-default-instances-old-locale-0.0.1 Building music-dynamics-literal-1.9.0... Configuring tf-random-0.5... Installed music-dynamics-literal-1.9.0 Building tf-random-0.5... Configuring StateVar-1.1.0.4... Installed text-1.2.2.1 Building StateVar-1.1.0.4... Configuring music-pitch-literal-1.9.0... Installed tf-random-0.5 Building music-pitch-literal-1.9.0... Configuring tagged-0.8.5... Installed StateVar-1.1.0.4 Building tagged-0.8.5... Installed music-pitch-literal-1.9.0 Configuring vector-space-0.10.4... Building vector-space-0.10.4... Configuring data-default-0.7.1.1... Installed tagged-0.8.5 Building data-default-0.7.1.1... Configuring hashable-1.2.4.0... Installed data-default-0.7.1.1 Building hashable-1.2.4.0... Configuring parsec-3.1.11... Installed vector-space-0.10.4 Building parsec-3.1.11... Configuring xml-1.3.14... Installed hashable-1.2.4.0 Building xml-1.3.14... Configuring QuickCheck-2.9.2... Installed xml-1.3.14 Installed parsec-3.1.11 Configuring distributive-0.5.0.2... Building QuickCheck-2.9.2... Building distributive-0.5.0.2... Configuring constraints-0.8... Installed distributive-0.5.0.2 Building constraints-0.8... Configuring void-0.7.1... Installed constraints-0.8 Building void-0.7.1... Configuring type-unary-0.3.0... Installed void-0.7.1 Building type-unary-0.3.0... Configuring contravariant-1.4... Installed QuickCheck-2.9.2 Building contravariant-1.4... Installed type-unary-0.3.0 Configuring musicxml2-1.9.0... Building musicxml2-1.9.0... Configuring HCodecs-0.5... Installed contravariant-1.4 Building HCodecs-0.5... Configuring comonad-5... Installed musicxml2-1.9.0 Building comonad-5... Installed HCodecs-0.5 Configuring hamid-0.10... Building hamid-0.10... Installed comonad-5 Configuring bifunctors-5.4.1... Building bifunctors-5.4.1... Installed hamid-0.10 Configuring reenact-0.9... Building reenact-0.9... Installed reenact-0.9 Installed bifunctors-5.4.1 Configuring semigroupoids-5.1... Building semigroupoids-5.1... Installed semigroupoids-5.1 Configuring music-score-1.2.2... Building music-score-1.2.2... Failed to install music-score-1.2.2 Build log ( /home/builder/.cabal/logs/music-score-1.2.2.log ): cabal: Entering directory '/tmp/cabal-tmp-16858/music-score-1.2.2' Configuring music-score-1.2.2... Building music-score-1.2.2... Preprocessing library music-score-1.2.2... [ 1 of 14] Compiling Music.Score.Duration ( src/Music/Score/Duration.hs, dist/build/Music/Score/Duration.o ) [ 2 of 14] Compiling Music.Score.Time ( src/Music/Score/Time.hs, dist/build/Music/Score/Time.o ) [ 3 of 14] Compiling Music.Score.Part ( src/Music/Score/Part.hs, dist/build/Music/Score/Part.o ) [ 4 of 14] Compiling Music.Score.Score ( src/Music/Score/Score.hs, dist/build/Music/Score/Score.o ) [ 5 of 14] Compiling Music.Score.Ties ( src/Music/Score/Ties.hs, dist/build/Music/Score/Ties.o ) [ 6 of 14] Compiling Music.Score.Pitch ( src/Music/Score/Pitch.hs, dist/build/Music/Score/Pitch.o ) [ 7 of 14] Compiling Music.Score.Rhythm ( src/Music/Score/Rhythm.hs, dist/build/Music/Score/Rhythm.o ) [ 8 of 14] Compiling Music.Score.Track ( src/Music/Score/Track.hs, dist/build/Music/Score/Track.o ) [ 9 of 14] Compiling Music.Score.Voice ( src/Music/Score/Voice.hs, dist/build/Music/Score/Voice.o ) src/Music/Score/Voice.hs:108:9: error: • Non type-variable argument in the constraint: Eq (Voice a1) (Use FlexibleContexts to permit this) • When checking the inferred type extract :: forall (m :: * -> *) a. (HasVoice a, Eq (Voice a), MonadPlus m) => Voice a -> m a -> m a In an equation for ‘voices’: voices sc = fmap (flip extract $ sc) (getVoices sc) where extract v = mfilter ((== v) . getVoice) cabal: Leaving directory '/tmp/cabal-tmp-16858/music-score-1.2.2' cabal: Error: some packages failed to install: music-score-1.2.2 failed during the building phase. The exception was: ExitFailure 1