Fix build dependencies

.travis.yml

@@ -1,6 +1,38 @@
 language: haskell
-ghc:
-  - 7.6
-  - 7.8
-script:
-  - cabal install --dependencies-only && cabal build
+
+env:
+  - GHCVER=7.6.3
+  - GHCVER=7.8.2
+  - GHCVER=7.8.3
+
+before_install:
+  # If $GHCVER is the one travis has, don't bother reinstalling it.
+  # We can also have faster builds by installing some libraries with
+  # `apt`. If it isn't, install the GHC we want from hvr's PPA along
+  # with cabal-1.18.
+  - |
+    if [ $GHCVER = `ghc --numeric-version` ]; then
+      # Try installing some of the build-deps with apt-get for speed.
+      travis/cabal-apt-install --enable-tests $MODE
+      export CABAL=cabal
+    else
+      # Install the GHC we want from hvr's PPA
+      travis_retry sudo add-apt-repository -y ppa:hvr/ghc
+      travis_retry sudo apt-get update
+      travis_retry sudo apt-get install cabal-install-1.18 ghc-$GHCVER happy
+      export CABAL=cabal-1.18
+      export PATH=/opt/ghc/$GHCVER/bin:$PATH
+    fi
+  # Uncomment whenever hackage is down.
+  # - mkdir -p ~/.cabal && cp travis/config ~/.cabal/config && $CABAL update
+  - $CABAL update
+
+  # Update happy when building with GHC head
+  - |
+    if [ $GHCVER = "7.8.3" ] || [ $GHCVER = "7.8.2" ]; then
+      $CABAL install happy alex
+      export PATH=$HOME/.cabal/bin:$PATH
+    fi
+
+install:
+  - $CABAL install --dependencies-only --enable-tests && $CABAL build

haskell/LTHaskellClient.hs

@@ -18,7 +18,7 @@ import qualified Data.ByteString.Lazy.Char8 as BS
 
 import           GHC.Generics               (Generic)
 import           Language.Haskell.GhcMod    (check, defaultOptions, findCradle,
-                                             lintSyntax, withGHC)
+                                             lint, runGhcModT)
 
 import           Language.Haskell.Stylish
 
@@ -166,10 +166,10 @@ format x = do
 
 getSyntaxIssues :: FilePath -> IO [String]
 getSyntaxIssues filePath = do
-  cradle <- findCradle
-  withGHC filePath $ check defaultOptions cradle [filePath]
+  (Right result, _) <- runGhcModT defaultOptions $ check [filePath]
+  return $ either (:[]) lines result
 
 getLintIssues :: FilePath -> IO [String]
 getLintIssues file = do
-  syntaxIssues <- lintSyntax defaultOptions file
-  return $ lines syntaxIssues
+  (Right lintIssues, _) <- runGhcModT defaultOptions $ lint file
+  return $ lines lintIssues

light-haskell.cabal

@@ -51,15 +51,15 @@ executable light-haskell
 
   -- Other library packages from which modules are imported.
   build-depends:
-    base ==4.6.*,
-    network ==2.4.*,
+    base (>=4.0 && <5),
+    network >=2.4,
     directory ==1.2.*,
     containers ==0.5.*,
     text ==1.1.*,
     bytestring ==0.10.*,
     aeson ==0.7.*,
-    process ==1.1.*,
-    ghc-mod ==3.1.*,
+    process >=1.1,
+    ghc-mod >=5.1,
     stylish-haskell ==0.5.*
 
   -- Directories containing source files.