Нужно было обновить пакет base, для этого поставил свежий ghc-7.2.1 из ppa.
$> cabal update
Downloading the latest package list from hackage.haskell.org
Note: there is a new version of cabal-install available.
To upgrade, run: cabal install cabal-install
$> cabal install cabal-install
Resolving dependencies...
cabal: cannot configure unix-2.4.2.0. It requires base >=4.2 && <4.4
For the dependency on base >=4.2 && <4.4 there are these packages:
base-4.2.0.0, base-4.2.0.1, base-4.2.0.2, base-4.3.0.0 and base-4.3.1.0.
However none of them are available.
base-4.2.0.0 was excluded because base-4.4.0.0 was selected instead
base-4.2.0.0 was excluded because of the top level dependency base -any
base-4.2.0.1 was excluded because base-4.4.0.0 was selected instead
base-4.2.0.1 was excluded because of the top level dependency base -any
base-4.2.0.2 was excluded because base-4.4.0.0 was selected instead
base-4.2.0.2 was excluded because of the top level dependency base -any
base-4.3.0.0 was excluded because base-4.4.0.0 was selected instead
base-4.3.0.0 was excluded because of the top level dependency base -any
base-4.3.1.0 was excluded because base-4.4.0.0 was selected instead
base-4.3.1.0 was excluded because of the top level dependency base -any
Следующее я вообще не понимаю
$> cabal install --reinstall monadrandom
Resolving dependencies...
Configuring MonadRandom-0.1.6...
Preprocessing library MonadRandom-0.1.6...
Building MonadRandom-0.1.6...
[1 of 2] Compiling Control.Monad.Random.Class ( Control/Monad/Random/Class.hs, dist/build/Control/Monad/Random/Class.o )
[2 of 2] Compiling Control.Monad.Random ( Control/Monad/Random.hs, dist/build/Control/Monad/Random.o )
Control/Monad/Random.hs:56:9:
Illegal datatype context (use -XDatatypeContexts): RandomGen g =>
cabal: Error: some packages failed to install:
MonadRandom-0.1.6 failed during the building phase. The exception was:
ExitFailure 1
Лучше наверняка было бы поставить ghc-7.0.4, он хотя бы стабильный? Не могу найти соответствующего ppa.