Resolving dependencies...
Downloading acme-realworld-0.1...
Configuring acme-realworld-0.1...
Building acme-realworld-0.1...
Preprocessing library acme-realworld-0.1...
[1 of 1] Compiling Acme.RealWorld   ( Acme/RealWorld.hs, dist/build/Acme/RealWorld.o )

Acme/RealWorld.hs:69:25:
    Ambiguous occurrence ‘bracket’
    It could refer to either ‘Control.Exception.bracket’,
                             imported from ‘Control.Exception’ at Acme/RealWorld.hs:23:27-33
                             (and originally defined in ‘Control.Exception.Base’)
                          or ‘GHC.IO.bracket’,
                             imported from ‘GHC.IO’ at Acme/RealWorld.hs:24:1-13
Failed to install acme-realworld-0.1
cabal: Error: some packages failed to install:
acme-realworld-0.1 failed during the building phase. The exception was:
ExitFailure 1