[fix build with more recent hint or something else
Helmut Grohne <grohne@cs.uni-bonn.de>**20140701122311
 Ignore-this: fc33b4234eb4231ffb3cc485e2252de0
 
 IOInterpreter started exposing build errors:
 
 src/IOInterpreter.hs:52:27:
     No instance for (MonadCatchIO-transformers-0.3.1.0:Control.Monad.CatchIO.MonadCatchIO
                        (InterpreterT IO))
       arising from a use of `catch'
 ...
 src/IOInterpreter.hs:52:35:
     No instance for (Control.Monad.Error.Class.MonadError
                        InterpreterError (InterpreterT IO))
       arising from a use of `handler'
 ...
 
 This likely is due to changes in the hint package (0.4.2.0 at this time). The
 solution involves adding the exceptions package and switching to those
 primitives.
] hunk ./igor2.cabal 27
-    MonadCatchIO-mtl >=0.2, pointless-haskell -any
+    MonadCatchIO-mtl >=0.2, pointless-haskell -any, exceptions
hunk ./src/IOInterpreter.hs 8
-import Control.Monad.CatchIO ( catch )
---import Control.Exception.Extensible hiding ( catch )
+import Control.Monad.Catch (catch, throwM)
hunk ./src/IOInterpreter.hs 57
-handler (SomeException e) = throwError . GhcException . show $ e
+handler :: SomeException -> Interpreter String
+handler (SomeException e) = throwM . GhcException . show $ e