Resolving dependencies...
Configuring heap-1.0.3...
Building heap-1.0.3...
Installed heap-1.0.3
Configuring median-stream-0.4.0.0...
Building median-stream-0.4.0.0...
Failed to install median-stream-0.4.0.0
Build log ( /home/builder/.cabal/logs/median-stream-0.4.0.0.log ):
cabal: Entering directory '/tmp/cabal-tmp-30226/median-stream-0.4.0.0'
Configuring median-stream-0.4.0.0...
Building median-stream-0.4.0.0...
Preprocessing library median-stream-0.4.0.0...
[1 of 1] Compiling Data.MedianStream ( src/Data/MedianStream.hs, dist/build/Data/MedianStream.o )

src/Data/MedianStream.hs:87:23: error:
    Ambiguous occurrence ‘empty’
    It could refer to either ‘Control.Applicative.empty’,
                             imported from ‘Control.Applicative’ at src/Data/MedianStream.hs:26:1-26
                             (and originally defined in ‘GHC.Base’)
                          or ‘Data.MedianStream.empty’,
                             defined at src/Data/MedianStream.hs:53:1
cabal: Leaving directory '/tmp/cabal-tmp-30226/median-stream-0.4.0.0'
cabal: Error: some packages failed to install:
median-stream-0.4.0.0 failed during the building phase. The exception was:
ExitFailure 1