optparse-applicative is a haskell library for parsing options on the 
command line, providing a powerful applicative interface for composing 
these options.

optparse-applicative takes care of reading and validating the arguments 
passed to the command line, handling and reporting errors, generating a 
usage line, a comprehensive help screen, and enabling context-sensitive 
bash completions.

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