[GHC] #14273: Typed holes' "valid substitutions" suggestions are oblivious to type class constraints (was: Typed holes are oblivious to type class constraints)

[GHC]

#14273: Typed holes' "valid substitutions" suggestions are oblivious to type class
constraints
-------------------------------------+-------------------------------------
        Reporter:  RyanGlScott       |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler (Type    |              Version:  8.3
  checker)                           |
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  Poor/confusing    |  Unknown/Multiple
  error message                      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:  #9091             |  Differential Rev(s):
       Wiki Page:                    |
-------------------------------------+-------------------------------------
Changes (by RyanGlScott):

 * cc: Tritlo (added)
 * related:   => #9091


Comment:

 Ah, I was not aware of that ticket! Thanks, kosmikus.

 As noted in the original comment, there are really two bugs here:

 1. The lack of reporting about type class constraints in typed hole error
 messages. This, as it turns out, is essentially a duplicate of #9091.
 2. The incorrect "valid substitution" suggestions. I move to make this
 ticket about that portion specifically. To this end, I've cc'd Tritlo, the
 author of these valid substitution suggestions.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14273#comment:4>
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