Resolving dependencies... Configuring old-locale-1.0.0.7... Configuring mtl-2.2.1... Building mtl-2.2.1... Building old-locale-1.0.0.7... Installed old-locale-1.0.0.7 Configuring primitive-0.6.1.0... Building primitive-0.6.1.0... Configuring random-1.1... Installed mtl-2.2.1 Building random-1.1... Configuring utf8-string-1.0.1.1... Installed primitive-0.6.1.0 Building utf8-string-1.0.1.1... Configuring text-1.2.2.1... Installed random-1.1 Building text-1.2.2.1... Installed utf8-string-1.0.1.1 Configuring vector-0.11.0.0... Building vector-0.11.0.0... Installed text-1.2.2.1 Configuring hashable-1.2.4.0... Building hashable-1.2.4.0... Configuring parsec-3.1.11... Installed hashable-1.2.4.0 Building parsec-3.1.11... Installed parsec-3.1.11 Installed vector-0.11.0.0 Configuring hashtables-1.2.1.0... Building hashtables-1.2.1.0... Installed hashtables-1.2.1.0 Configuring gtk2hs-buildtools-0.13.2.1... Building gtk2hs-buildtools-0.13.2.1... Installed gtk2hs-buildtools-0.13.2.1 Configuring cairo-0.13.3.1... Configuring glib-0.13.4.1... Building glib-0.13.4.1... Building cairo-0.13.3.1... Installed cairo-0.13.3.1 Installed glib-0.13.4.1 Configuring pango-0.13.3.1... Configuring gio-0.13.3.1... Building gio-0.13.3.1... Building pango-0.13.3.1... Installed pango-0.13.3.1 Installed gio-0.13.3.1 Configuring gtk-0.14.6... Building gtk-0.14.6... Installed gtk-0.14.6 Configuring buster-0.99.2... Building buster-0.99.2... Failed to install buster-0.99.2 Build log ( /home/builder/.cabal/logs/buster-0.99.2.log ): cabal: Entering directory '/tmp/cabal-tmp-22461/buster-0.99.2' Configuring buster-0.99.2... Warning: The 'license-file' field refers to the file '' which does not exist. Building buster-0.99.2... Preprocessing library buster-0.99.2... [1 of 4] Compiling App.EventBus ( App/EventBus.hs, dist/build/App/EventBus.o ) App/EventBus.hs:156:10: error: • Illegal instance declaration for ‘Monoid (Behaviour a)’ (All instance types must be of the form (T a1 ... an) where a1 ... an are *distinct type variables*, and each type variable appears at most once in the instance head. Use FlexibleInstances if you want to disable this.) • In the instance declaration for ‘Monoid (Behaviour a)’ cabal: Leaving directory '/tmp/cabal-tmp-22461/buster-0.99.2' cabal: Error: some packages failed to install: buster-0.99.2 failed during the building phase. The exception was: ExitFailure 1