Resolving dependencies... Configuring phantom-state-0.2.1.2... Building phantom-state-0.2.1.2... Installed phantom-state-0.2.1.2 Downloading binary-list-0.3.4.0... Configuring binary-list-0.3.4.0... Building binary-list-0.3.4.0... Failed to install binary-list-0.3.4.0 Build log ( /home/builder/.cabal/logs/binary-list-0.3.4.0.log ): cabal: Entering directory '/tmp/cabal-tmp-23338/binary-list-0.3.4.0' Configuring binary-list-0.3.4.0... Building binary-list-0.3.4.0... Preprocessing library binary-list-0.3.4.0... [1 of 3] Compiling Data.BinaryList.Internal ( Data/BinaryList/Internal.hs, dist/build/Data/BinaryList/Internal.o ) [2 of 3] Compiling Data.BinaryList ( Data/BinaryList.hs, dist/build/Data/BinaryList.o ) Data/BinaryList.hs:112:25: error: Ambiguous occurrence ‘length’ It could refer to either ‘Data.Foldable.length’, imported from ‘Data.Foldable’ at Data/BinaryList.hs:87:23-35 or ‘Data.BinaryList.length’, defined at Data/BinaryList.hs:108:1 Data/BinaryList.hs:112:38: error: Ambiguous occurrence ‘length’ It could refer to either ‘Data.Foldable.length’, imported from ‘Data.Foldable’ at Data/BinaryList.hs:87:23-35 or ‘Data.BinaryList.length’, defined at Data/BinaryList.hs:108:1 Data/BinaryList.hs:440:10: error: Ambiguous occurrence ‘length’ It could refer to either ‘Data.Foldable.length’, imported from ‘Data.Foldable’ at Data/BinaryList.hs:87:23-35 or ‘Data.BinaryList.length’, defined at Data/BinaryList.hs:108:1 cabal: Leaving directory '/tmp/cabal-tmp-23338/binary-list-0.3.4.0' cabal: Error: some packages failed to install: binary-list-0.3.4.0 failed during the building phase. The exception was: ExitFailure 1