[GHC] #13371: instance selection too eager

[GHC]

#13371: instance selection too eager
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        Reporter:  aavogt            |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler (Type    |              Version:  8.0.2
  checker)                           |
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by niteria):

 Broken GHC infers:

 {{{
 g_f :: forall (b :: k0) k c a. F a (Proxy b) => a -> c
 }}}
 , while the working one infers
 {{{
 g_f :: forall k (b :: k) c a. F a (Proxy b) => a -> c
 }}}

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13371#comment:5>
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