[GHC] #10134: Pattern Matching Causes Infinite Type Error

[GHC]

#10134: Pattern Matching Causes Infinite Type Error
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        Reporter:  dongen            |                   Owner:
            Type:  bug               |                  Status:  new
        Priority:  normal            |               Milestone:
       Component:  Compiler          |                 Version:  7.8.4
      Resolution:                    |                Keywords:
Operating System:  Unknown/Multiple  |            Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |               Test Case:
      Blocked By:                    |                Blocking:
 Related Tickets:                    |  Differential Revisions:
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Comment (by goldfire):

 `TypeFamilies` without `MonoLocalBinds` is an unsupported configuration.
 The user manual, section 7.13.9.3 (on let-generalization) concludes with
 this:

 > The flag `-XMonoLocalBinds` is implied by `-XTypeFamilies` and
 `-XGADTs`. You can switch it off again with `-XNoMonoLocalBinds` but type
 inference becomes less predicatable if you do so. (Read the papers!)

 So it seems this is clash's problem, after all, in setting a wonky
 configuration. I think this ticket can be closed as invalid, but one of
 the posters should double-check me before closing.

 Thanks, @thomie, for the analysis!

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10134#comment:20>
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