Configuring hs-fltk-0.2.5...
Building hs-fltk-0.2.5...
Preprocessing library hs-fltk-0.2.5...
[ 1 of 12] Compiling Graphics.UI.FLTK.Widget ( src/Graphics/UI/FLTK/Widget.hs, dist/dist-sandbox-7ea82ab6/build/Graphics/UI/FLTK/Widget.o )

src/Graphics/UI/FLTK/Widget.hs:20:1: Warning:
    The import of ‘Foreign.StablePtr’ is redundant
      except perhaps to import instances from ‘Foreign.StablePtr’
    To import instances alone, use: import Foreign.StablePtr()

src/Graphics/UI/FLTK/Widget.hs:37:21: Warning:
    Defined but not used: ‘g’

src/Graphics/UI/FLTK/Widget.hs:110:1: Warning:
    Top-level binding with no type signature: wNever :: When

src/Graphics/UI/FLTK/Widget.hs:112:1: Warning:
    Top-level binding with no type signature: wChanged :: When

src/Graphics/UI/FLTK/Widget.hs:114:1: Warning:
    Top-level binding with no type signature: wRelease :: When

src/Graphics/UI/FLTK/Widget.hs:116:1: Warning:
    Top-level binding with no type signature: wReleaseAllways :: When

src/Graphics/UI/FLTK/Widget.hs:118:1: Warning:
    Top-level binding with no type signature: wEnter :: When

src/Graphics/UI/FLTK/Widget.hs:120:1: Warning:
    Top-level binding with no type signature: wEnterAllways :: When

src/Graphics/UI/FLTK/Widget.hs:122:1: Warning:
    Top-level binding with no type signature: wEnterChanged :: When

src/Graphics/UI/FLTK/Widget.hs:124:1: Warning:
    Top-level binding with no type signature: wNotChanged :: When

src/Graphics/UI/FLTK/Widget.hs:142:1: Warning:
    Top-level binding with no type signature:
      callbackHandler :: forall t. t -> StablePtr (t -> IO ()) -> IO ()

src/Graphics/UI/FLTK/Widget.hs:152:1: Warning:
    Defined but not used: ‘nothing’

src/Graphics/UI/FLTK/Widget.hs:152:1: Warning:
    Top-level binding with no type signature:
      nothing :: forall t (m :: * -> *). Monad m => t -> m ()

src/Graphics/UI/FLTK/Widget.hs:164:1: Warning:
    Top-level binding with no type signature: black :: Color

src/Graphics/UI/FLTK/Widget.hs:165:1: Warning:
    Top-level binding with no type signature: red :: Color

src/Graphics/UI/FLTK/Widget.hs:166:1: Warning:
    Top-level binding with no type signature: green :: Color

src/Graphics/UI/FLTK/Widget.hs:167:1: Warning:
    Top-level binding with no type signature: yellow :: Color

src/Graphics/UI/FLTK/Widget.hs:168:1: Warning:
    Top-level binding with no type signature: blue :: Color

src/Graphics/UI/FLTK/Widget.hs:169:1: Warning:
    Top-level binding with no type signature: magenta :: Color

src/Graphics/UI/FLTK/Widget.hs:170:1: Warning:
    Top-level binding with no type signature: cyan :: Color

src/Graphics/UI/FLTK/Widget.hs:171:1: Warning:
    Top-level binding with no type signature: white :: Color

src/Graphics/UI/FLTK/Widget.hs:228:1: Warning:
    Top-level binding with no type signature:
      getCoords :: Ptr Widget -> Ptr Int -> IO (Int, Int, Int, Int)

src/Graphics/UI/FLTK/Widget.hs:229:25: Warning:
    This binding for ‘w’ shadows the existing binding
      bound at src/Graphics/UI/FLTK/Widget.hs:228:11
[ 2 of 12] Compiling Graphics.UI.FLTK.Menu ( src/Graphics/UI/FLTK/Menu.hs, dist/dist-sandbox-7ea82ab6/build/Graphics/UI/FLTK/Menu.o )

src/Graphics/UI/FLTK/Menu.hs:19:29: Warning:
    This binding for ‘w’ shadows the existing binding
      bound at src/Graphics/UI/FLTK/Menu.hs:19:16

src/Graphics/UI/FLTK/Menu.hs:31:6: Warning:
    Defined but not used: ‘mb’

src/Graphics/UI/FLTK/Menu.hs:35:9: Warning:
    This binding for ‘label’ shadows the existing binding
      imported from ‘Graphics.UI.FLTK.Widget’ at src/Graphics/UI/FLTK/Menu.hs:12:1-30
      (and originally defined at src/Graphics/UI/FLTK/Widget.hs:87:1-5)

src/Graphics/UI/FLTK/Menu.hs:41:1: Warning:
    Top-level binding with no type signature: mDefault :: MenuType

src/Graphics/UI/FLTK/Menu.hs:42:1: Warning:
    Top-level binding with no type signature: mInactive :: MenuType

src/Graphics/UI/FLTK/Menu.hs:43:1: Warning:
    Top-level binding with no type signature: mToggle :: MenuType

src/Graphics/UI/FLTK/Menu.hs:44:1: Warning:
    Top-level binding with no type signature: mValue :: MenuType

src/Graphics/UI/FLTK/Menu.hs:45:1: Warning:
    Top-level binding with no type signature: mRadio :: MenuType

src/Graphics/UI/FLTK/Menu.hs:46:1: Warning:
    Top-level binding with no type signature: mInvisible :: MenuType

src/Graphics/UI/FLTK/Menu.hs:47:1: Warning:
    Top-level binding with no type signature: mDivider :: MenuType
[ 3 of 12] Compiling Graphics.UI.FLTK.Input ( src/Graphics/UI/FLTK/Input.hs, dist/dist-sandbox-7ea82ab6/build/Graphics/UI/FLTK/Input.o )

src/Graphics/UI/FLTK/Input.hs:21:10:
    Illegal instance declaration for ‘Value_FC Input String’
      (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 ‘Value_FC Input String’