Resolving dependencies... Configuring base-orphans-0.5.4... Configuring cereal-0.4.1.1... Building cereal-0.4.1.1... Building base-orphans-0.5.4... Installed base-orphans-0.5.4 Configuring mtl-2.2.1... Building mtl-2.2.1... Configuring prelude-extras-0.4.0.3... Installed cereal-0.4.1.1 Building prelude-extras-0.4.0.3... Configuring safe-0.3.10... Installed mtl-2.2.1 Building safe-0.3.10... Configuring semigroups-0.18.2... Installed safe-0.3.10 Building semigroups-0.18.2... Configuring stm-2.4.4.1... Installed prelude-extras-0.4.0.3 Building stm-2.4.4.1... Configuring primitive-0.6.1.0... Installed semigroups-0.18.2 Building primitive-0.6.1.0... Configuring transformers-compat-0.5.1.4... Installed stm-2.4.4.1 Building transformers-compat-0.5.1.4... Configuring text-1.2.2.1... Installed transformers-compat-0.5.1.4 Building text-1.2.2.1... Configuring unexceptionalio-0.3.0... Installed primitive-0.6.1.0 Building unexceptionalio-0.3.0... Installed unexceptionalio-0.3.0 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 mmorph-1.0.9... Installed exceptions-0.8.3 Building mmorph-1.0.9... Configuring tagged-0.8.5... Installed mmorph-1.0.9 Building tagged-0.8.5... Configuring vector-0.11.0.0... Installed tagged-0.8.5 Building vector-0.11.0.0... Configuring errors-2.1.3... Installed text-1.2.2.1 Building errors-2.1.3... Installed errors-2.1.3 Configuring distributive-0.5.0.2... Building distributive-0.5.0.2... Configuring pipes-4.1.9... Installed distributive-0.5.0.2 Building pipes-4.1.9... Configuring hashable-1.2.4.0... Installed pipes-4.1.9 Building hashable-1.2.4.0... Configuring pipes-parse-3.0.8... Installed hashable-1.2.4.0 Building pipes-parse-3.0.8... Installed pipes-parse-3.0.8 Configuring unordered-containers-0.2.7.1... Building unordered-containers-0.2.7.1... Configuring void-0.7.1... Installed vector-0.11.0.0 Building void-0.7.1... Installed void-0.7.1 Configuring contravariant-1.4... Building contravariant-1.4... Configuring hashtables-1.2.1.0... Installed unordered-containers-0.2.7.1 Building hashtables-1.2.1.0... Installed contravariant-1.4 Configuring comonad-5... Building comonad-5... Installed hashtables-1.2.1.0 Configuring cereal-plus-0.3.1... Building cereal-plus-0.3.1... Failed to install cereal-plus-0.3.1 Build log ( /home/builder/.cabal/logs/cereal-plus-0.3.1.log ): cabal: Entering directory '/tmp/cabal-tmp-1235/cereal-plus-0.3.1' Configuring cereal-plus-0.3.1... Building cereal-plus-0.3.1... Preprocessing library cereal-plus-0.3.1... [1 of 4] Compiling CerealPlus.Prelude ( src/CerealPlus/Prelude.hs, dist/build/CerealPlus/Prelude.o ) src/CerealPlus/Prelude.hs:9:5: error: Ambiguous occurrence ‘?:’ It could refer to either ‘Exports.?:’, imported from ‘Control.Error’ at src/CerealPlus/Prelude.hs:97:1-31 (and originally defined in ‘Control.Error.Util’) or ‘CerealPlus.Prelude.?:’, defined at src/CerealPlus/Prelude.hs:117:8 src/CerealPlus/Prelude.hs:10:5: error: Ambiguous occurrence ‘traceM’ It could refer to either ‘Exports.traceM’, imported from ‘Debug.Trace’ at src/CerealPlus/Prelude.hs:49:1-29 or ‘CerealPlus.Prelude.traceM’, defined at src/CerealPlus/Prelude.hs:121:1 cabal: Leaving directory '/tmp/cabal-tmp-1235/cereal-plus-0.3.1' Installed comonad-5 Configuring bifunctors-5.4.1... Building bifunctors-5.4.1... Installed bifunctors-5.4.1 Configuring semigroupoids-5.1... Configuring profunctors-5.2... 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 pipes-group-1.0.6... Building pipes-group-1.0.6... Installed pipes-group-1.0.6 Configuring pipes-bytestring-2.1.4... Building pipes-bytestring-2.1.4... Installed pipes-bytestring-2.1.4 cabal: Error: some packages failed to install: cereal-plus-0.3.1 failed during the building phase. The exception was: ExitFailure 1 pipes-cereal-plus-0.3.0 depends on cereal-plus-0.3.1 which failed to install.