cabal: cannot configure AERN-Real-2011.1.0.1. It requires base >=4 && <4.3
For the dependency on base >=4 && <4.3 there are these packages: base-4.0.0.0,
base-4.1.0.0, base-4.2.0.0, base-4.2.0.1 and base-4.2.0.2. However none of
them are available.
base-4.0.0.0 was excluded because of the top level dependency base -any
base-4.1.0.0 was excluded because of the top level dependency base -any
base-4.2.0.0 was excluded because of the top level dependency base -any
base-4.2.0.1 was excluded because of the top level dependency base -any
base-4.2.0.2 was excluded because of the top level dependency base -any