[GHC] #7057: Simplifier infinite loop regression

[GHC]

#7057: Simplifier infinite loop regression
--------------------------------+-------------------------------------------
 Reporter:  ronwalf             |          Owner:                  
     Type:  bug                 |         Status:  new             
 Priority:  normal              |      Component:  Compiler        
  Version:  7.4.2               |       Keywords:                  
       Os:  Unknown/Multiple    |   Architecture:  Unknown/Multiple
  Failure:  Compile-time crash  |       Testcase:                  
Blockedby:                      |       Blocking:                  
  Related:                      |  
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 GHC gets stuck in the simplifier when compiling the attached file,
 eventually exhausting all ram.
 Compiling gives:
 {{{
 $ ghc -v3 -O --make ghcloop.hs
 Glasgow Haskell Compiler, Version 7.4.2, stage 2 booted by GHC version
 7.0.3
 ...
 *** Simplifier:
 ^C*** Deleting temp files:
 ...
 }}}

 Running with with all the dump flags suggests the fault is pddlDocExpr's.
 I'm finding it hard to create a smaller example, as even silly things like
 removing the container (or not using Data.Generics) restore termination.

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/7057>
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