cabal: cannot configure checkers-0.2.6. It requires QuickCheck >=2.1.0.2
For the dependency on QuickCheck >=2.1.0.2 there are these packages:
QuickCheck-2.1.0.2 and QuickCheck-2.1.0.3. However none of them are available.
QuickCheck-2.1.0.2 was excluded because reactive-0.8.6 requires QuickCheck
<2.0
QuickCheck-2.1.0.3 was excluded because reactive-0.8.6 requires QuickCheck
<2.0