[GHC] #13742: Code using ConstraintKinds needs explicit kind signature with GHC 8.2.1

[GHC]

#13742: Code using ConstraintKinds needs explicit kind signature with GHC 8.2.1
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        Reporter:  albertov          |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  highest           |            Milestone:
       Component:  Compiler (Type    |              Version:  8.2.1-rc2
  checker)                           |             Keywords:
      Resolution:                    |  ConstraintKinds, KindSignatures
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:                    |
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Comment (by goldfire):

 Adding it: maybe a day's work. (That's quite a lot, in the scheme of
 things.) Maintaining it forever: more than that. Nevertheless, I do think
 this is where we're headed...

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13742#comment:7>
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