SlackBuildsOrg/haskell/haskell-syb

Syb Haskell library contains the generics system described in the
Scrap Your Boilerplate papers.  It defines the Data class of types
permitting folding and unfolding of constructor applications,
instances of this class for primitive types, and a variety of
traversals.

After uninstalling, run this command to unregister the package from
the ghc package database:   ghc-pkg recache