Resolving dependencies...
Downloading ixmonad-0.50...
Configuring ixmonad-0.50...
Building ixmonad-0.50...
Preprocessing library ixmonad-0.50...

src/Control/Effect/State.hs:4:14:
    Unsupported extension: AllowAmbiguousTypes
Failed to install ixmonad-0.50
cabal: Error: some packages failed to install:
ixmonad-0.50 failed during the building phase. The exception was:
ExitFailure 1