From cbfa26eb1647b149f37f2d1639a6b6d47fa23acc Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20Gr=C3=B6ber?= <dxld@darkboxed.org>
Date: Fri, 14 Aug 2015 03:48:29 +0200
Subject: [PATCH] Make sure cabal-helper is ready before invoking dumpsym

---
 Language/Haskell/GhcMod/CabalHelper.hs | 9 +++++++++
 Language/Haskell/GhcMod/Internal.hs    | 2 ++
 src/GHCMod.hs                          | 1 +
 3 files changed, 12 insertions(+)

diff --git a/Language/Haskell/GhcMod/CabalHelper.hs b/Language/Haskell/GhcMod/CabalHelper.hs
index 36c82a1..006607b 100644
--- a/Language/Haskell/GhcMod/CabalHelper.hs
+++ b/Language/Haskell/GhcMod/CabalHelper.hs
@@ -20,6 +20,7 @@ module Language.Haskell.GhcMod.CabalHelper
   ( getComponents
   , getGhcMergedPkgOptions
   , getPackageDbStack
+  , prepareCabalHelper
   )
 #endif
   where
@@ -126,6 +127,14 @@ getComponents = chCached Cached {
                  , a == a'
                  ]
 
+prepareCabalHelper :: (IOish m, GmEnv m, GmLog m) => m ()
+prepareCabalHelper = do
+  crdl <- cradle
+  let projdir = cradleRootDir crdl
+      distdir = projdir </> "dist"
+  readProc <- gmReadProcess
+  liftIO $ prepare readProc projdir distdir
+
 withCabal :: (IOish m, GmEnv m, GmLog m) => m a -> m a
 withCabal action = do
     crdl <- cradle
diff --git a/Language/Haskell/GhcMod/Internal.hs b/Language/Haskell/GhcMod/Internal.hs
index bb9fae7..143dc5f 100644
--- a/Language/Haskell/GhcMod/Internal.hs
+++ b/Language/Haskell/GhcMod/Internal.hs
@@ -52,6 +52,7 @@ module Language.Haskell.GhcMod.Internal (
   , GmComponent(..)
   , GmComponentType(..)
   , GmModuleGraph(..)
+  , prepareCabalHelper
   ) where
 
 import GHC.Paths (libdir)
@@ -65,6 +66,7 @@ import Language.Haskell.GhcMod.Monad
 import Language.Haskell.GhcMod.Types
 import Language.Haskell.GhcMod.Utils
 import Language.Haskell.GhcMod.World
+import Language.Haskell.GhcMod.CabalHelper
 
 -- | Obtaining the directory for ghc system libraries.
 ghcLibDir :: FilePath
diff --git a/src/GHCMod.hs b/src/GHCMod.hs
index 57c914e..06156f9 100644
--- a/src/GHCMod.hs
+++ b/src/GHCMod.hs
@@ -371,6 +371,7 @@ globalCommands _       = Nothing
 legacyInteractive :: IOish m => GhcModT m ()
 legacyInteractive = do
     opt <- options
+    prepareCabalHelper
     symdbreq <- liftIO $ newSymDbReq opt
     world <- getCurrentWorld
     legacyInteractiveLoop symdbreq world