Fix compile for cabal 2 and ghc 8.2.2

Author: code5hot

.travis.yml

@@ -52,6 +52,9 @@ matrix:
     - env: CABALVER=1.24 GHCVER=8.0.1 HAPPYVER=1.19.5
       compiler: ": #GHC 8.0.1"
       addons: {apt: {packages: [cabal-install-1.24,ghc-8.0.1,happy-1.19.5], sources: [hvr-ghc]}}
+    - env: CABALVER=2.0 GHCVER=8.2.2 HAPPYVER=1.19.5
+      compiler: ": #GHC 8.2.2"
+      addons: {apt: {packages: [cabal-install-2,ghc-8.2.2,happy-1.19.5], sources: [hvr-ghc]}}
 
 before_install:
  - unset CC

src/System/Eval/Haskell.hs

@@ -52,7 +52,7 @@ import Data.Dynamic             ( Dynamic )
 import Data.Typeable            ( Typeable )
 
 import Data.Either              ( )
-import Data.Map as Map
+import Data.Map as Map hiding   ( take )
 import Data.Char
 
 import System.IO                ( )

src/System/Plugins/Env.hs

@@ -69,7 +69,7 @@ import System.IO.Error          ( catch, ioError, isDoesNotExistError )
 
 import Control.Concurrent.MVar  ( MVar(), newMVar, withMVar )
 
-import Distribution.Package hiding (depends, packageName, PackageName(..)
+import Distribution.Package hiding (Module, depends, packageName, PackageName(..)
 #if MIN_VERSION_ghc(7,10,0)
                                    , installedPackageId
 #endif

src/System/Plugins/Load.hs

@@ -74,7 +74,9 @@ import BinIface
 import HscTypes
 
 import Module (moduleName, moduleNameString)
-#if MIN_VERSION_ghc(8,0,0)
+#if MIN_VERSION_ghc(8,2,0)
+import Module (installedUnitIdString)
+#elif MIN_VERSION_ghc(8,0,0)
 import Module (unitIdString)
 #elif MIN_VERSION_ghc(7,10,0)
 import Module (packageKeyString)
@@ -710,7 +712,9 @@ loadDepends obj incpaths = do
 
                 -- and find some packages to load, as well.
                 let ps = dep_pkgs ds
-#if MIN_VERSION_ghc(8,0,0)
+#if MIN_VERSION_ghc(8,2,0)
+                ps' <- filterM loaded . map installedUnitIdString . nub $ map fst ps
+#elif MIN_VERSION_ghc(8,0,0)
                 ps' <- filterM loaded . map unitIdString . nub $ map fst ps
 #elif MIN_VERSION_ghc(7,10,0)
                 ps' <- filterM loaded . map packageKeyString . nub $ map fst ps