This package is meant to be imported as

 import Facebook.Persistent () 

because it doesn't export any symbols. However, it exports the following orphan instances:

 instance PersistField Action -- since 0.1 instance PersistField Id -- since 0.1.2 instance PersistField AppAccessToken -- since 0.1.3 instance PersistField UserAccessToken -- since 0.1.3