@hackage fail4.9.0.0

This package contains the Control.Monad.Fail module providing the MonadFail class that became available in base-4.9.0.0 for older base package versions.

This package turns into an empty package when used with GHC versions which already provide the Control.Monad.Fail module to make way for GHC's own Control.Monad.Fail module.