Resolving dependencies...
Configuring ghc-paths-0.1.0.9...
Configuring haddock-library-1.4.3...
Building haddock-library-1.4.3...
Building ghc-paths-0.1.0.9...
Installed ghc-paths-0.1.0.9
Installed haddock-library-1.4.3
Configuring haddock-api-2.17.4...
Building haddock-api-2.17.4...
Failed to install haddock-api-2.17.4
Build log ( /home/builder/.cabal/logs/haddock-api-2.17.4.log ):
cabal: Entering directory '/tmp/cabal-tmp-24858/haddock-api-2.17.4'
Configuring haddock-api-2.17.4...
Building haddock-api-2.17.4...
Preprocessing library haddock-api-2.17.4...
[ 1 of 38] Compiling Paths_haddock_api ( dist/build/autogen/Paths_haddock_api.hs, dist/build/Paths_haddock_api.o )
[ 2 of 38] Compiling Haddock.Version  ( src/Haddock/Version.hs, dist/build/Haddock/Version.o )
[ 3 of 38] Compiling Haddock.Syb      ( src/Haddock/Syb.hs, dist/build/Haddock/Syb.o )
[ 4 of 38] Compiling Haddock.Parser   ( src/Haddock/Parser.hs, dist/build/Haddock/Parser.o )
[ 5 of 38] Compiling Haddock.GhcUtils ( src/Haddock/GhcUtils.hs, dist/build/Haddock/GhcUtils.o )

src/Haddock/GhcUtils.hs:20:1: warning: [-Wunused-imports]
    The import of ‘Data.Function’ is redundant
      except perhaps to import instances from ‘Data.Function’
    To import instances alone, use: import Data.Function()

src/Haddock/GhcUtils.hs:27:1: warning: [-Wunused-imports]
    The import of ‘RdrName’ is redundant
      except perhaps to import instances from ‘RdrName’
    To import instances alone, use: import RdrName()

src/Haddock/GhcUtils.hs:28:1: warning: [-Wunused-imports]
    The import of ‘GhcMonad’ is redundant
      except perhaps to import instances from ‘GhcMonad’
    To import instances alone, use: import GhcMonad()

src/Haddock/GhcUtils.hs:30:1: warning: [-Wunused-imports]
    The import of ‘UniqFM’ is redundant
      except perhaps to import instances from ‘UniqFM’
    To import instances alone, use: import UniqFM()
[ 6 of 38] Compiling Haddock.Backends.Xhtml.Types ( src/Haddock/Backends/Xhtml/Types.hs, dist/build/Haddock/Backends/Xhtml/Types.o )
[ 7 of 38] Compiling Haddock.Backends.Hyperlinker.Types ( src/Haddock/Backends/Hyperlinker/Types.hs, dist/build/Haddock/Backends/Hyperlinker/Types.o )
[ 8 of 38] Compiling Haddock.Types    ( src/Haddock/Types.hs, dist/build/Haddock/Types.o )

src/Haddock/Types.hs:454:10: error:
    Duplicate instance declarations:
      instance NFData Name -- Defined at src/Haddock/Types.hs:454:10
      instance NFData Name -- Defined in ‘Name’

src/Haddock/Types.hs:455:10: error:
    Duplicate instance declarations:
      instance NFData OccName -- Defined at src/Haddock/Types.hs:455:10
      instance NFData OccName -- Defined in ‘OccName’

src/Haddock/Types.hs:456:10: error:
    Duplicate instance declarations:
      instance NFData ModuleName
        -- Defined at src/Haddock/Types.hs:456:10
      instance NFData ModuleName -- Defined in ‘Module’
cabal: Leaving directory '/tmp/cabal-tmp-24858/haddock-api-2.17.4'
cabal: Error: some packages failed to install:
haddock-api-2.17.4 failed during the building phase. The exception was:
ExitFailure 1