Hi, I am trying to install the Euterpea library, which depends on glfw, but it is failing to install with a compilation failure. Could someone take a look at the error and tell me what might be wrong? Many Thanks Martin The Glorious Glasgow Haskell Compilation System, version 7.10.1 cabal-install version 1.22.4.0 using version 1.22.3.0 of the Cabal library $ cabal update $ cabal install glfw Resolving dependencies... Configuring GLFW-0.5.2.2... Failed to install GLFW-0.5.2.2 Build log ( /home/martin/.cabal/logs/GLFW-0.5.2.2.log ): cabal: Error: some packages failed to install: GLFW-0.5.2.2 failed during the configure step. The exception was: user error ('/home/martin/.ghc/bin/ghc' exited with an error: /tmp/GLFW-0.5.2.2-20349/GLFW-0.5.2.2/dist/setup/setup.hs:106:14: No instance for (Applicative (StateT ConfState IO)) arising from a use of ‘modify’ In the expression: modify In the expression: modify $ \ (ConfState fs ls) -> ConfState fs (lib : ls) In an equation for ‘addLib’: addLib lib = modify $ \ (ConfState fs ls) -> ConfState fs (lib : ls) /tmp/GLFW-0.5.2.2-20349/GLFW-0.5.2.2/dist/setup/setup.hs:242:10: Could not deduce (Applicative (StateT s m)) arising from the superclasses of an instance declaration from the context (Monad m) bound by the instance declaration at /tmp/GLFW-0.5.2.2-20349/GLFW-0.5.2.2/dist/setup/setup.hs:242:10-40 In the instance declaration for ‘Monad (StateT s m)’ /tmp/GLFW-0.5.2.2-20349/GLFW-0.5.2.2/dist/setup/setup.hs:252:10: Could not deduce (Applicative (StateT s m)) arising from the superclasses of an instance declaration from the context (Monad m) bound by the instance declaration at /tmp/GLFW-0.5.2.2-20349/GLFW-0.5.2.2/dist/setup/setup.hs:252:10-47 In the instance declaration for ‘MonadState s (StateT s m)’ )