Resolving dependencies... Downloading WordNet-0.1.1... Configuring WordNet-0.1.1... Warning: Instead of 'ghc-options: -cpp' use 'extensions: CPP' Building WordNet-0.1.1... Preprocessing library WordNet-0.1.1... on the commandline: Warning: -fglasgow-exts is deprecated: Use individual extensions instead NLP/WordNet.hs:71:18: Could not find module `Data.Set' It is a member of the hidden package `containers-0.5.0.0'. Perhaps you need to add `containers' to the build-depends in your .cabal file. Use -v to see a list of the files searched for. Failed to install WordNet-0.1.1 cabal: Error: some packages failed to install: WordNet-0.1.1 failed during the building phase. The exception was: ExitFailure 1