[GHC] #12237: Constraint resolution vs. type family resolution vs. TypeErrors

[GHC]

#12237: Constraint resolution vs. type family resolution vs. TypeErrors
-------------------------------------+-------------------------------------
        Reporter:  cactus            |                Owner:
            Type:  feature request   |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  8.0.1
      Resolution:                    |             Keywords:
                                     |  CustomTypeErrors
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  Other             |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:  #11990            |  Differential Rev(s):
       Wiki Page:                    |
-------------------------------------+-------------------------------------
Changes (by thomie):

 * cc: diatchki (added)
 * related:   => #11990


Comment:

 This seems fixed in GHC HEAD (c88f31a08943764217b69adb1085ba423c9bcf91,
 8.1.20160610), perhaps as a result of #11990.

 {{{
 Test.hs:23:16: error:
     • Unsupported type: Int
     • In the second argument of ‘($)’, namely
         ‘foo (Proxy :: Proxy (Int, ()))’
       In the expression: print $ foo (Proxy :: Proxy (Int, ()))
       In an equation for ‘main’:
           main = print $ foo (Proxy :: Proxy (Int, ()))
 }}}

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12237#comment:2>
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