anchor.diff:      addUnverified email verkey =
           runDB $ insert $ User email Nothing (Just verkey) False
   
  -    sendVerifyEmail email _ verurl =
  +    sendVerifyEmail email _ verurl = do
  +        -- Print out to the console the verification email, for easier
  +        -- debugging.
  +        liftIO $ putStrLn $ "Copy/ Paste this URL in your browser:" ++ unpack verurl
  +
  +        -- Send email.
           liftIO $ renderSendMail (emptyMail $ Address Nothing "noreply")
               { mailTo = [Address Nothing email]
               , mailHeaders =
  
positive.code: import           Control.Monad            (join)
  import           Control.Monad.Logger (runNoLoggingT)
  import           Data.Maybe               (isJust)
  import           Data.Text                (Text)
  import qualified Data.Text.Lazy.Encoding
  import           Data.Typeable            (Typeable)
  import           Database.Persist.Sqlite
  
negative.code: Let's have a look at a site that provides email authentication, storing
  passwords in a Persistent SQLite database.
  
  NOTE: Even if you don't have an email server, for debugging purposes the
  verification link is printed in the console.
  
  [source, haskell]
  ----
  {-# LANGUAGE DeriveDataTypeable         #-}
  