[GHC] #15974: QuantifiedConstraints: Spurious error involving superclass constraints

[GHC]

#15974: QuantifiedConstraints: Spurious error involving superclass constraints
-------------------------------------+-------------------------------------
        Reporter:  lexi.lambda       |                Owner:  (none)
            Type:  bug               |               Status:  closed
        Priority:  normal            |            Milestone:  8.6.3
       Component:  Compiler          |              Version:  8.6.2
      Resolution:  invalid           |             Keywords:
                                     |  QuantifiedConstraints
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  GHC rejects       |  Unknown/Multiple
  valid program                      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
-------------------------------------+-------------------------------------

Comment (by lexi.lambda):

 > If you agree, would you like to close as invalid?

 Yes, I have already done so, though I appreciate the confirmation that my
 reasoning was correct. Sorry for the noise!

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/15974#comment:3>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler