[GHC] #5395: Context reduction stack overflow without undecidable instances

[GHC]

#5395: Context reduction stack overflow without undecidable instances
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    Reporter:  guest                     |        Owner:                           
        Type:  bug                       |       Status:  new                      
    Priority:  normal                    |    Milestone:                           
   Component:  Compiler                  |      Version:  7.0.4                    
    Keywords:  type family, termination  |     Testcase:                           
   Blockedby:                            |   Difficulty:                           
          Os:  Unknown/Multiple          |     Blocking:                           
Architecture:  Unknown/Multiple          |      Failure:  GHC rejects valid program
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Comment(by guest):

 I'm fine with the increased threshold.  The largest
 context-stack--limit I used is 180.

 It would be nice to include the phrase
  The trouble is that some module you import may have used
  `-XUndecidableInstances`, and that could cause your compilation to
  diverge, even if you are ery well behaved.
 in the documentation (in the section about `UndecidableInstances`).

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Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/5395#comment:2>
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