[Haskell-beginners] Issue installing reactive-banana-5.0.0.1

Hi It appears I can’t install reactive-banana-5.0.0.1: cabal install reactive-banana Resolving dependencies... cabal: cannot configure mtl-2.1. It requires transformers ==0.3.* For the dependency on transformers ==0.3.* there are these packages: transformers-0.3.0.0. However none of them are available. transformers-0.3.0.0 was excluded because reactive-banana-0.5.0.1 requires transformers ==0.2.* How can I solve this ? thank you, Miguel