adding checks for broken packages

ihaskell.cabal

@@ -101,6 +101,7 @@ library
                    IHaskell.IPython
                    IHaskell.Flags
                    IHaskell.Types
+                   IHaskell.BrokenPackages
   other-modules: 
                    Paths_ihaskell
 
@@ -125,6 +126,7 @@ executable IHaskell
              IHaskell.Flags
              IHaskell.Types
              IHaskell.Display
+             IHaskell.BrokenPackages
 
   default-extensions: DoAndIfThenElse
   

src/IHaskell/BrokenPackages.hs

+{-# LANGUAGE OverloadedStrings, NoImplicitPrelude #-}
+module IHaskell.BrokenPackages (getBrokenPackages) where
+
+import ClassyPrelude hiding ((<|>))
+
+import Text.Parsec
+import Text.Parsec.String
+import Control.Applicative hiding ((<|>), many)
+
+import Shelly
+
+data BrokenPackage = BrokenPackage {
+        packageID :: String,
+        brokenDeps :: [String]
+      }
+
+instance Show BrokenPackage where
+  show = packageID
+
+getBrokenPackages :: IO [String]
+getBrokenPackages = shellyNoDir $ do
+  silently $ errExit False $ run "ghc-pkg" ["check"]
+  checkOut <- lastStderr
+  
+  return $ case parse (many check) "ghc-pkg output" $ unpack checkOut of
+    Left err -> []
+    Right pkgs -> map show pkgs
+
+check :: Parser BrokenPackage
+check = string "There are problems in package "
+        >> BrokenPackage <$> ident <* string ":\n" <*> many1 dependency
+
+ident :: Parser String
+ident = many (alphaNum <|> oneOf "-.")
+
+dependency :: Parser String
+dependency = string "  dependency \"" *> ident <* string "\" doesn't exist\n"

src/IHaskell/Eval/Evaluate.hs

@@ -68,6 +68,7 @@ import IHaskell.Eval.Lint
 import IHaskell.Display
 import qualified IHaskell.Eval.Hoogle as Hoogle
 import IHaskell.Eval.Util
+import IHaskell.BrokenPackages
 
 import Paths_ihaskell (version)
 import Data.Version (versionBranch)
@@ -148,6 +149,7 @@ initializeImports = do
   -- XXX this will try to load broken packages, provided they depend
   -- on the right ihaskell version
   dflags <- getSessionDynFlags
+  broken <- liftIO getBrokenPackages
   displayPackages <- liftIO $ do
     (dflags, _) <- initPackages dflags
     let Just db = pkgDatabase dflags
@@ -175,6 +177,7 @@ initializeImports = do
         displayPkgs = [ pkgName
                   | pkgName <- packageNames,
                     Just (x:_) <- [stripPrefix initStr pkgName],
+                    pkgName `notElem` broken,
                     isAlpha x]
 
     return displayPkgs

src/IHaskell/Types.hs

@@ -36,6 +36,8 @@ import            Text.ParserCombinators.ReadP
 
 import IPython.Kernel
 
+data Test = Test
+
 data ViewFormat
      = Pdf
      | Html