diff --git a/ChangeLog b/ChangeLog
new file mode 100644
--- /dev/null
+++ b/ChangeLog
@@ -0,0 +1,7 @@
+May 28 2014
+Release 0.2
+Report filename given an error.
+Avoid parsing within comments.
+
+May 20 2014
+Initial release 0.1
diff --git a/HListPP.cabal b/HListPP.cabal
--- a/HListPP.cabal
+++ b/HListPP.cabal
@@ -1,5 +1,5 @@
 name:                HListPP
-version:             0.1
+version:             0.2
 synopsis:            A preprocessor for HList labelable labels
 description:         A preprocessor that replaces @`longDescriptiveName@ with
                     .
@@ -42,6 +42,7 @@
 category:            Development
 build-type:          Simple
 cabal-version:       >=1.10
+extra-source-files:  ChangeLog
 
 library
   default-language: Haskell2010
diff --git a/HListPP.hs b/HListPP.hs
--- a/HListPP.hs
+++ b/HListPP.hs
@@ -7,6 +7,9 @@
 import Data.Monoid
 import System.Environment
 import Text.Regex.Applicative
+import Control.Exception
+import System.Exit
+import System.IO
 
 -- "ModuleName."
 modNameDot = [ado|
@@ -28,21 +31,32 @@
 
 addLabel xu = "(hLens' (Label :: Label \""++xu++"\"))"
 
-main = operate =<< getArgs
+main = do
+  args <- getArgs
+  operate args
+    `catch` \ (SomeException e) -> do
+          hPutStrLn stderr (show e)
+          hPutStrLn stderr ("in: HListPP " ++ unwords args)
+          exitFailure
 
 {-# INLINE operate #-}
 operate [originalFileName, inputFile, outputFile] = do
     input <- readFile inputFile
     let linePragma = "{-# LINE 1 \"" <> originalFileName <> "\" #-}\n"
     writeFile outputFile (linePragma <> s input)
-operate _ = error "usage: HListPP originalFileName inputFile outputFile\
+operate args = error $ "usage: HListPP originalFileName inputFile outputFile\
   \ also: \
-  \ {-# OPTIONS_GHC -F -pgmF HListPP #-}"
+  \ {-# OPTIONS_GHC -F -pgmF HListPP #-}\
+  \ called with arguments: " ++ show args
 
--- | applies takeQual outside of characters, strings
+-- | applies takeQual outside of characters, strings, comments
 {-# INLINE s #-}
 s (stripPrefix "'\"'" -> Just xs) = "'\"'" ++ s xs
 s (stripPrefix "'`'"  -> Just xs) = "'`'"  ++ s xs
+s (stripPrefix "{-" -> Just xs) = "{-" ++ cl xs
+s (stripPrefix "--" -> Just xs)
+        | x1 : _ <- xs, isSymbol x1 = "--" ++ s xs
+        | otherwise = "-- " ++ cs xs
 s ('"': xs) = '"' : t xs
 s ('`':  (takeQual -> (a,xs))) = a ++ s xs
 s (x:xs) = x : s xs
@@ -53,4 +67,14 @@
 t (stripPrefix "\\\"" -> Just xs) = "\\\"" ++ t xs
 t ('"' : xs) = '"' : s xs
 t (x:xs) = x : t xs
+t [] = error "expected \""
 
+-- | inside multiline comment
+cl (stripPrefix "-}" -> Just xs) = "-}" ++ s xs
+cl (x:xs) = x:cl xs
+cl [] = error "expected -}"
+
+-- | inside single line comment
+cs ('\n':xs) = '\n' : s xs
+cs (x:xs) = x : cs xs
+cs "" = ""