Resolving dependencies... Downloading logict-0.2... [1 of 1] Compiling Main ( /tmp/logict-0.2-15651/logict-0.2/Setup.lhs, /tmp/logict-0.2-15651/logict-0.2/dist/setup/Main.o ) Linking /tmp/logict-0.2-15651/logict-0.2/dist/setup/setup ... Configuring logict-0.2... Warning: No 'build-type' specified. If you do not need a custom Setup.hs or ./configure script then use 'build-type: Simple'. Building logict-0.2... Preprocessing library logict-0.2... [1 of 2] Compiling Control.Monad.Logic.Class ( Control/Monad/Logic/Class.hs, dist/build/Control/Monad/Logic/Class.o ) [2 of 2] Compiling Control.Monad.Logic ( Control/Monad/Logic.hs, dist/build/Control/Monad/Logic.o ) Control/Monad/Logic.hs:66:36: Illegal symbol '.' in type Perhaps you intended -XRankNTypes or similar flag to enable explicit-forall syntax: forall . Failed to install logict-0.2 cabal: Error: some packages failed to install: logict-0.2 failed during the building phase. The exception was: ExitFailure 1