[GHC] #3108: Do a better job of solving recursive type-class constraints with functional dependencies

[GHC]

#3108: Do a better job of solving recursive type-class constraints with functional
dependencies
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    Reporter:  simonpj                  |       Owner:                  
        Type:  bug                      |      Status:  new             
    Priority:  high                     |   Milestone:  7.6.1           
   Component:  Compiler (Type checker)  |     Version:  6.10.1          
    Keywords:                           |          Os:  Unknown/Multiple
Architecture:  Unknown/Multiple         |     Failure:  None/Unknown    
  Difficulty:  Unknown                  |    Testcase:                  
   Blockedby:                           |    Blocking:                  
     Related:                           |  
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Comment(by simonpj):

 Turns out that the new constraint solver is doing the Right Thing; but it
 has a `pprTrace` that emits messages when it should not.

 Dimitrios, can you
  * Commit the fix to `pprTrace`?
  * Add the above program to the testsuite, in `typecheck/should_compile`?

 Thanks

 Simon

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/3108#comment:8>
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