From 692ba50962806a77f5c612a8c9b2a9aa5733df0d Mon Sep 17 00:00:00 2001
From: Thomas Tuegel <ttuegel@gmail.com>
Date: Wed, 31 Aug 2016 21:59:28 -0500
Subject: [PATCH] Respect GHC_PACKAGE_PATH

Fixes #3728. Fixes #2711.
---
 Cabal/Distribution/Simple/GHC.hs   | 13 ++++++-------
 Cabal/Distribution/Simple/GHCJS.hs | 14 +++++++-------
 2 files changed, 13 insertions(+), 14 deletions(-)

diff --git a/Cabal/Distribution/Simple/GHC.hs b/Cabal/Distribution/Simple/GHC.hs
index af2309315b3..a2801958c3e 100644
--- a/Cabal/Distribution/Simple/GHC.hs
+++ b/Cabal/Distribution/Simple/GHC.hs
@@ -86,6 +86,7 @@ import Distribution.Text
 import Distribution.Utils.NubList
 import Language.Haskell.Extension
 
+import Distribution.Compat.Environment ( lookupEnv )
 import qualified Data.Map as Map
 import Data.Version             ( showVersion )
 import System.Directory
@@ -93,7 +94,7 @@ import System.Directory
          , canonicalizePath, removeFile )
 import System.FilePath          ( (</>), (<.>), takeExtension
                                 , takeDirectory, replaceExtension
-                                , isRelative )
+                                , isRelative, searchPathSeparator )
 import qualified System.Info
 
 -- -----------------------------------------------------------------------------
@@ -283,9 +284,11 @@ getInstalledPackages :: Verbosity -> Compiler -> PackageDBStack
                      -> ProgramConfiguration
                      -> IO InstalledPackageIndex
 getInstalledPackages verbosity comp packagedbs conf = do
-  checkPackageDbEnvVar
   checkPackageDbStack comp packagedbs
-  pkgss <- getInstalledPackages' verbosity packagedbs conf
+  envPackageDBs <- maybe []
+                   (map SpecificPackageDB . unintersperse searchPathSeparator)
+                   <$> lookupEnv "GHC_PACKAGE_PATH"
+  pkgss <- getInstalledPackages' verbosity (envPackageDBs ++ packagedbs) conf
   index <- toPackageIndex verbosity pkgss conf
   return $! hackRtsPackage index
 
@@ -351,10 +354,6 @@ getUserPackageDB _verbosity ghcProg (Platform arch os) = do
       | otherwise                        = "package.conf"
     Just ghcVersion = programVersion ghcProg
 
-checkPackageDbEnvVar :: IO ()
-checkPackageDbEnvVar =
-    Internal.checkPackageDbEnvVar "GHC" "GHC_PACKAGE_PATH"
-
 checkPackageDbStack :: Compiler -> PackageDBStack -> IO ()
 checkPackageDbStack comp = if flagPackageConf implInfo
                               then checkPackageDbStackPre76
diff --git a/Cabal/Distribution/Simple/GHCJS.hs b/Cabal/Distribution/Simple/GHCJS.hs
index f59fb6b9cb1..e0723feb85f 100644
--- a/Cabal/Distribution/Simple/GHCJS.hs
+++ b/Cabal/Distribution/Simple/GHCJS.hs
@@ -48,7 +48,9 @@ import Language.Haskell.Extension
 import qualified Data.Map as Map
 import System.Directory         ( doesFileExist )
 import System.FilePath          ( (</>), (<.>), takeExtension
-                                , takeDirectory, replaceExtension )
+                                , takeDirectory, replaceExtension
+                                , searchPathSeparator )
+import Distribution.Compat.Environment ( lookupEnv )
 
 configure :: Verbosity -> Maybe FilePath -> Maybe FilePath
           -> ProgramConfiguration
@@ -187,9 +189,11 @@ getPackageDBContents verbosity packagedb conf = do
 getInstalledPackages :: Verbosity -> PackageDBStack -> ProgramConfiguration
                      -> IO InstalledPackageIndex
 getInstalledPackages verbosity packagedbs conf = do
-  checkPackageDbEnvVar
   checkPackageDbStack packagedbs
-  pkgss <- getInstalledPackages' verbosity packagedbs conf
+  envPackageDBs <- maybe []
+                   (map SpecificPackageDB . unintersperse searchPathSeparator)
+                   <$> lookupEnv "GHCJS_PACKAGE_PATH"
+  pkgss <- getInstalledPackages' verbosity (envPackageDBs ++ packagedbs) conf
   index <- toPackageIndex verbosity pkgss conf
   return $! index
 
@@ -209,10 +213,6 @@ toPackageIndex verbosity pkgss conf = do
   where
     Just ghcjsProg = lookupProgram ghcjsProgram conf
 
-checkPackageDbEnvVar :: IO ()
-checkPackageDbEnvVar =
-    Internal.checkPackageDbEnvVar "GHCJS" "GHCJS_PACKAGE_PATH"
-
 checkPackageDbStack :: PackageDBStack -> IO ()
 checkPackageDbStack (GlobalPackageDB:rest)
   | GlobalPackageDB `notElem` rest = return ()