Resolving dependencies... Configuring acme-realworld-0.1... Building acme-realworld-0.1... Failed to install acme-realworld-0.1 Build log ( /home/builder/.cabal/logs/acme-realworld-0.1.log ): cabal: Entering directory '/tmp/cabal-tmp-30254/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: error: 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 cabal: Leaving directory '/tmp/cabal-tmp-30254/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