[Haskell-cafe] Safe lens?

Why are getters from the 'lens' package unsafe? Is there a subset like Data.Label.Pure from 'fclabels' that can be imported safely? $ cat a.hs {-# LANGUAGE Safe #-} import Control.Lens.Getter main = print 123 $ runghc a.hs a.hs:3:1: Control.Lens.Getter: Can't be safely imported! The module itself isn't safe. Thanks, Greg