Hi, With the attached file, say Printf.hs, GHCi 7.6.3 works as follows: % ghci Printf.hs [1 of 1] Compiling Printf ( Printf.hs, interpreted ) Ok, modules loaded: Printf. > :set -XTemplateHaskell > putStrLn ( $(pr "Hello") ) Hello "Hello" is printed. Good. However, with GHC 7.8, the following error occurs: % ghci Printf.hs [1 of 1] Compiling Printf ( Printf.hs, interpreted ) Ok, modules loaded: Printf. > :set -XTemplateHaskell > putStrLn ( $(pr "Hello") ) unknown package: main Is this a bug of Template Haskell of GHC 7.8? --Kazu {-# LANGUAGE TemplateHaskell #-} -- -- derived from: http://www.haskell.org/ghc/docs/latest/html/users_guide/template-haskell.htm... -- module Printf (pr) where import Language.Haskell.TH data Format = D | S | L String parse :: String -> [Format] parse s = [ L s ] gen :: [Format] -> Q Exp gen [D] = [| \n -> show n |] gen [S] = [| \s -> s |] gen [L s] = stringE s -- | -- -- >>> :set -XTemplateHaskell -- >>> putStrLn ( $(pr "Hello") ) -- Hello pr :: String -> Q Exp pr s = gen (parse s)