From 7474968486d9b2c84d428ddf802471971f1807df Mon Sep 17 00:00:00 2001
From: Kazu Yamamoto <kazu@iij.ad.jp>
Date: Wed, 15 Feb 2012 13:58:04 +0900
Subject: [PATCH] fixing terrible bug on Maybe.

---
 Cabal.hs | 8 ++++----
 Gap.hs   | 8 ++++++++
 2 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/Cabal.hs b/Cabal.hs
index 40f611c..c1e79b0 100644
--- a/Cabal.hs
+++ b/Cabal.hs
@@ -34,7 +34,7 @@ initializeGHC opt fileName ghcOptions logging =
         return (fileName,logReader)
     withCabal = do
         (owdir,cdir,cfile) <- liftIO getDirs
-        binfo <- parseCabalFile cfile
+        binfo <- liftIO $ parseCabalFile cfile
         let (idirs',exts',mlang) = extractBuildInfo binfo
             exts = map addX exts'
             lang = maybe "-XHaskell98" addX mlang
@@ -51,10 +51,10 @@ initializeGHC opt fileName ghcOptions logging =
 ----------------------------------------------------------------
 
 -- Causes error, catched in the upper function.
-parseCabalFile :: FilePath -> Ghc BuildInfo
+parseCabalFile :: FilePath -> IO BuildInfo
 parseCabalFile file = do
-    cabal <- liftIO $ readPackageDescription silent file
-    return . fromJust $ fromLibrary cabal >> fromExecutable cabal
+    cabal <- readPackageDescription silent file
+    return . fromJust $ fromLibrary cabal <|> fromExecutable cabal
   where
     fromLibrary c     = libBuildInfo . condTreeData <$> condLibrary c
     fromExecutable c  = buildInfo . condTreeData . snd <$> toMaybe (condExecutables c)
diff --git a/Gap.hs b/Gap.hs
index 20ad2e6..e2e1286 100644
--- a/Gap.hs
+++ b/Gap.hs
@@ -31,6 +31,14 @@ import HscTypes (liftIO)
 import Pretty
 #endif
 
+{-
+pretty :: Outputable a => a -> String
+pretty = showSDocForUser neverQualify . ppr
+
+debug :: Outputable a => a -> b -> b
+debug x v = trace (pretty x) v
+-}
+
 ----------------------------------------------------------------
 ----------------------------------------------------------------