fixing #118.

CabalApi.hs

@@ -12,7 +12,7 @@ module CabalApi (
 import Control.Applicative
 import Control.Exception (throwIO)
 import Data.List (intercalate)
-import Data.Maybe (maybeToList, listToMaybe, fromMaybe)
+import Data.Maybe (maybeToList, listToMaybe, fromJust)
 import Data.Set (fromList, toList)
 import Distribution.Package (Dependency(Dependency), PackageName(PackageName))
 import Distribution.PackageDescription
@@ -71,7 +71,7 @@ getGHCOptions ghcOptions binfo = ghcOptions ++ exts ++ [lang] ++ libs ++ libDirs
 
 -- Causes error, catched in the upper function.
 cabalBuildInfo :: GenericPackageDescription -> BuildInfo
-cabalBuildInfo pd = fromMaybe emptyBuildInfo $ fromLibrary pd <|> fromExecutable pd
+cabalBuildInfo pd = fromJust $ fromLibrary pd <|> fromExecutable pd
   where
     fromLibrary c     = libBuildInfo . condTreeData <$> condLibrary c
     fromExecutable c  = buildInfo . condTreeData . snd <$> listToMaybe (condExecutables c)

GHCApi.hs

@@ -1,3 +1,5 @@
+{-# LANGUAGE ScopedTypeVariables #-}
+
 module GHCApi (
     withGHC
   , withGHCDummyFile
@@ -50,13 +52,17 @@ data Build = CabalPkg | SingleFile deriving Eq
 
 initializeFlagsWithCradle :: Options -> Cradle -> [GHCOption] -> Bool -> Ghc LogReader
 initializeFlagsWithCradle opt cradle ghcOptions logging
-  | cabal     = do
-      (gopts,idirs,depPkgs) <- liftIO $ fromCabalFile ghcOptions cradle
-      initSession CabalPkg opt gopts idirs (Just depPkgs) logging
-  | otherwise =
-      initSession SingleFile opt ghcOptions importDirs Nothing logging
+  | cabal     = withCabal `gcatch` fallback
+  | otherwise = withoutCabal
   where
     cabal = isJust $ cradleCabalFile cradle
+    withCabal = do
+        (gopts,idirs,depPkgs) <- liftIO $ fromCabalFile ghcOptions cradle
+        initSession CabalPkg opt gopts idirs (Just depPkgs) logging
+    withoutCabal =
+        initSession SingleFile opt ghcOptions importDirs Nothing logging
+    fallback :: SomeException -> Ghc LogReader
+    fallback _ = withoutCabal
 
 ----------------------------------------------------------------