diff --git a/dead-code-detection.cabal b/dead-code-detection.cabal
--- a/dead-code-detection.cabal
+++ b/dead-code-detection.cabal
@@ -3,7 +3,7 @@
 -- see: https://github.com/sol/hpack
 
 name:           dead-code-detection
-version:        0.5.1
+version:        0.6
 synopsis:       detect dead code in haskell projects
 description:    detect dead code in haskell projects
 category:       Development
@@ -52,7 +52,7 @@
 
 test-suite spec
   type: exitcode-stdio-1.0
-  main-is: Spec.hs
+  main-is: Main.hs
   hs-source-dirs:
       test
     , src
@@ -81,6 +81,7 @@
       GraphSpec
       Helper
       RunSpec
+      Spec
       Ast
       Ast.UsedNames
       Files
diff --git a/src/Ast.hs b/src/Ast.hs
--- a/src/Ast.hs
+++ b/src/Ast.hs
@@ -2,6 +2,7 @@
 {-# LANGUAGE FlexibleInstances #-}
 {-# LANGUAGE LambdaCase #-}
 {-# LANGUAGE NamedFieldPuns #-}
+{-# LANGUAGE ScopedTypeVariables #-}
 {-# LANGUAGE TupleSections #-}
 {-# LANGUAGE TypeSynonymInstances #-}
 {-# LANGUAGE ViewPatterns #-}
@@ -15,12 +16,14 @@
 
 import           Bag
 import           Control.Arrow ((>>>), second)
+import           Control.Exception
 import           Control.Monad
 import           Data.Data
 import           Data.Generics.Uniplate.Data
 import qualified GHC
 import           GHC hiding (Module, moduleName)
 import           GHC.Paths (libdir)
+import           HscTypes
 import           Name
 import           Outputable
 import           System.IO
@@ -80,10 +83,18 @@
         return $ Just $ map toModule typecheckedModules
 
 errorHandler :: IO (Maybe a) -> IO (Either String a)
-errorHandler action = do
-  (errs, a) <- hCapture [stderr] action
-  return $ maybe (Left errs) Right a
+errorHandler action =
+  catchSourceError $
+  captureStderr action
+  where
+    captureStderr action = do
+      (errs, a) <- hCapture [stderr] action
+      return $ maybe (Left errs) Right a
 
+    catchSourceError :: IO (Either String a) -> IO (Either String a)
+    catchSourceError = handle $ \ (e :: SourceError) ->
+      return $ Left $ show e
+
 findExports :: Ast -> [ModuleName] -> Either String [Name]
 findExports ast names = concat <$> mapM inner names
   where
@@ -136,7 +147,7 @@
 
 instance NameGraph (HsGroup Name) where
   nameGraph = \ case
-    HsGroup valBinds [] tyclds _instances _standaloneInstances [] [] foreign_decls [] [] [] [] [] ->
+    HsGroup valBinds [] tyclds _instances _standaloneInstances [] [] foreign_decls [] _annotations [] [] [] ->
       nameGraph valBinds ++
       nameGraph tyclds ++
       nameGraph foreign_decls
@@ -165,6 +176,7 @@
     VarPat p -> withoutUsedNames [p]
     TuplePat pats _ _ -> nameGraph pats
     WildPat _ -> []
+    LazyPat p -> nameGraph p
     pat -> errorNyiOutputable pat
 
 instance NameGraph (TyClGroup Name) where
diff --git a/src/Ast/UsedNames.hs b/src/Ast/UsedNames.hs
--- a/src/Ast/UsedNames.hs
+++ b/src/Ast/UsedNames.hs
@@ -53,6 +53,7 @@
     BangPat pat -> usedNames pat
     NPat{} -> []
     LitPat{} -> []
+    LazyPat pat -> usedNames pat
     x -> errorNyiOutputable x
 
 instance UsedNames (HsConDetails (LPat Name) (HsRecFields Name (LPat Name))) where
diff --git a/src/Run.hs b/src/Run.hs
--- a/src/Run.hs
+++ b/src/Run.hs
@@ -19,6 +19,7 @@
 import           GHC.Show
 import           Graph
 import qualified Paths_dead_code_detection as Paths
+import           Utils
 
 data Options
   = Options {
@@ -66,7 +67,7 @@
 deadNamesFromFiles files roots includeUnderscoreNames = do
   ast <- parse files
   case ast of
-    Left err -> die err
+    Left err -> die $ ghcError err
     Right ast -> case findExports ast roots of
       Left err -> die err
       Right rootExports -> do
@@ -75,6 +76,12 @@
           removeConstructorNames $
           filterUnderScoreNames includeUnderscoreNames $
           deadNames graph rootExports
+  where
+    ghcError message = stripSpaces $ unlines $
+      "Some of the input files produce compile errors." :
+      "ghc says:" :
+      map ("   " ++) (lines message) ++
+      []
 
 filterUnderScoreNames :: Bool -> [Name] -> [Name]
 filterUnderScoreNames include = if include then id else
diff --git a/src/Utils.hs b/src/Utils.hs
--- a/src/Utils.hs
+++ b/src/Utils.hs
@@ -2,6 +2,7 @@
 
 module Utils where
 
+import           Data.Char
 import           Data.Set
 
 nubOrd :: forall a . Ord a => [a] -> [a]
@@ -14,7 +15,7 @@
     inner _ [] = []
 
 errorNyi :: String -> a
-errorNyi message = error $ unlines $
+errorNyi message = error $ stripSpaces $ unlines $
   "Encountered a language construct that is" :
   "not yet implemented. Please consider opening a bug report about" :
   "this here: https://github.com/soenkehahn/dead-code-detection/issues" :
@@ -22,3 +23,8 @@
   "Here's some debugging output that will probably help to solve this problem:" :
   message :
   []
+
+stripSpaces :: String -> String
+stripSpaces =
+  reverse . dropWhile isSpace .
+  reverse . dropWhile isSpace
diff --git a/test/Ast/UsedNamesSpec.hs b/test/Ast/UsedNamesSpec.hs
--- a/test/Ast/UsedNamesSpec.hs
+++ b/test/Ast/UsedNamesSpec.hs
@@ -10,17 +10,18 @@
 
 spec :: Spec
 spec = do
-  let errs =
+  let errs :: [(String, ())]
+      errs =
         ("errorNyiData", errorNyiData ()) :
         ("errorNyiOutputable", errorNyiOutputable ()) :
         []
   forM_ errs $ \ (name, err) -> do
     describe name $ do
       it "explains that this is not yet implemented" $ do
-        err () `shouldThrow` \ (ErrorCall message) ->
+        seq err (return ()) `shouldThrow` \ (ErrorCall message) ->
           "not yet implemented" `isInfixOf` message
 
       it "points to the issue tracker" $ do
-        err () `shouldThrow` \ (ErrorCall message) ->
+        seq err (return ()) `shouldThrow` \ (ErrorCall message) ->
           "https://github.com/soenkehahn/dead-code-detection/issues" `isInfixOf`
             message
diff --git a/test/AstSpec.hs b/test/AstSpec.hs
--- a/test/AstSpec.hs
+++ b/test/AstSpec.hs
@@ -31,6 +31,11 @@
         result <- parse ["Foo.hs"]
         void result `shouldBe` Left "\nFoo.hs:2:7: Not in scope: ‘bar’\n"
 
+    it "handles missing modules gracefully" $ do
+      withFooHeader "import Bar" $ do
+        Left message <- parse ["Foo.hs"]
+        message `shouldContain` "Could not find module ‘Bar’"
+
     it "doesn't output error messages" $ do
       withFoo "foo = bar" $ do
         output <- hCapture_ [stdout, stderr] $ parse ["Foo.hs"]
@@ -175,6 +180,13 @@
       |] $ do
         (usageGraph <$> parseStringGraph ["Foo.hs"]) `shouldReturn` [("Foo.Foo", [])]
 
+    it "ignores annotations" $ do
+      withFooHeader [i|
+        {-# ANN foo "annotation" #-}
+        foo = 42
+      |] $ do
+        (usageGraph <$> parseStringGraph ["Foo.hs"]) `shouldReturn` [("Foo.foo",[])]
+
     context "PatBind" $ do
       it "can parse pattern binding" $ do
         withFooHeader [i|
@@ -186,6 +198,13 @@
       it "can parse tuple pattern binding" $ do
         withFooHeader [i|
           (a, b) = let x = x in x
+        |] $ do
+          parseStringGraph ["Foo.hs"] `shouldReturn`
+            Graph [("Foo.a", []), ("Foo.b", [])] []
+
+      it "can parse lazy patterns" $ do
+        withFooHeader [i|
+          ~(a, b) = let x = x in x
         |] $ do
           parseStringGraph ["Foo.hs"] `shouldReturn`
             Graph [("Foo.a", []), ("Foo.b", [])] []
diff --git a/test/Main.hs b/test/Main.hs
new file mode 100644
--- /dev/null
+++ b/test/Main.hs
@@ -0,0 +1,12 @@
+
+module Main where
+
+import           GHC (runGhc)
+import           GHC.Paths (libdir)
+
+import qualified Spec
+
+main :: IO ()
+main = do
+  runGhc (Just libdir) (return ())
+  Spec.main
diff --git a/test/RunSpec.hs b/test/RunSpec.hs
--- a/test/RunSpec.hs
+++ b/test/RunSpec.hs
@@ -58,6 +58,17 @@
       output `shouldContain` "version: "
 
   describe "deadNamesFromFiles" $ do
+    it "should clearly mark ghc's output as such" $ do
+      let a = ("A", [i|
+            module A where
+            import B
+          |])
+      withModules [a] $ do
+        output <- hCapture_ [stderr] $
+          deadNamesFromFiles ["A.hs"] [mkModuleName "A"] False
+            `shouldThrow` (== ExitFailure 1)
+        output `shouldContain` "ghc says:"
+
     it "can be run on multiple modules" $ do
       let a = ("A", [i|
             module A where
diff --git a/test/Spec.hs b/test/Spec.hs
--- a/test/Spec.hs
+++ b/test/Spec.hs
@@ -1,1 +1,1 @@
-{-# OPTIONS_GHC -F -pgmF hspec-discover #-}
+{-# OPTIONS_GHC -F -pgmF hspec-discover -optF --module-name=Spec #-}