[GHC] #7321: Compiler hangs when reading interface file

[GHC]

#7321: Compiler hangs when reading interface file
---------------------------------+------------------------------------------
    Reporter:  simonpj           |       Owner:                  
        Type:  bug               |      Status:  new             
    Priority:  normal            |   Milestone:                  
   Component:  Compiler          |     Version:  7.6.1           
    Keywords:                    |          Os:  Unknown/Multiple
Architecture:  Unknown/Multiple  |     Failure:  None/Unknown    
  Difficulty:  Unknown           |    Testcase:                  
   Blockedby:                    |    Blocking:                  
     Related:                    |  
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 Jeroen Weijers reports: I have two files `Data.hs` and `Class.hs` (`Class`
 depends on `Data`). When I compile `Class.hs` (`ghc --make Class.hs`) the
 ghc does what it should do.
 When I now make a change to `Class.hs` (add a newline to the end of the
 file for example) and try to run `ghc --make Class.hs` again the ghc gets
 stuck on recompiling `Class.hs`.

 {{{
 module Class where
   import Data
   foo :: Exp a
   foo = error "urk"

 {-# LANGUAGE GADTs #-}
 module Data where
   data Exp a where
      LamE :: (Exp a -> Exp b) -> Exp (Exp a -> Exp b)
 }}}

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/7321>
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