Description: Fixed ghc lib dir lookup via stack for system installed ghc
Author: Tomas Janousek <tomi@nomi.cz>
Origin: upstream, https://github.com/hdevtools/hdevtools/commit/a436699b8587a
Bug-Debian: https://bugs.debian.org/846023

Index: b/src/Stack.hs
===================================================================
--- a/src/Stack.hs
+++ b/src/Stack.hs
@@ -52,7 +52,11 @@ getStackGhcBinDir :: FilePath -> IO (May
 getStackGhcBinDir = fmap (fmap trim) . execStackInPath "path --compiler-bin"
 
 getStackGhcLibDir :: FilePath -> IO (Maybe FilePath)
-getStackGhcLibDir = fmap (fmap takeDirectory) . execStackInPath "path --global-pkg-db"
+getStackGhcLibDir p = do
+    ghc <- (trim <$>) <$> execStackInPath "path --compiler-exe" p
+    case ghc of
+        Just exe -> (trim <$>) <$> execInPath (exe ++ " --print-libdir") p
+        Nothing -> return Nothing
 
 getStackDist :: FilePath -> IO (Maybe FilePath)
 getStackDist p = (trim <$>) <$> execStackInPath "path --dist-dir" p