>     import qualified XMonad.StackSet as W
>
>     {- ... -}
>
>     followTo which wsel = withFocused $ \w -> do
>       moveTo which wsel
>       here <- gets $ tag . workspace . current . windowset
>       windows $ W.shift here w

Thank you.  Would you please pass along the imports you're using?  I
needed to add an 'import XMonad.StackSet' but on 'xmonad --recompile'