[GHC] #14860: QuantifiedConstraints: Can't quantify constraint involving type family

[GHC]

#14860: QuantifiedConstraints: Can't quantify constraint involving type family
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        Reporter:  RyanGlScott       |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler (Type    |              Version:  8.5
  checker)                           |             Keywords:
      Resolution:                    |  QuantifiedConstraints
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  GHC rejects       |  Unknown/Multiple
  valid program                      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:  #16123            |  Differential Rev(s):
       Wiki Page:                    |
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Changes (by RyanGlScott):

 * related:   => #16123


Comment:

 See #16123 for an example of a program which cannot work without the
 flattener receiving the upgrade described in comment:19.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14860#comment:22>
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