[GHC] #11198: TypeInType error message regressions

[GHC]

#11198: TypeInType error message regressions
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        Reporter:  goldfire          |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  high              |            Milestone:  8.2.2
       Component:  Compiler (Type    |              Version:  7.11
  checker)                           |             Keywords:  TypeInType,
      Resolution:                    |  TypeErrorMessages
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
                                     |  typecheck/should_fail/{T8262,T8603,tcfail122}
      Blocked By:                    |             Blocking:
 Related Tickets:  #11672            |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by goldfire):

 What test program inspired comment:18? I don't agree with some of your
 conclusions and want to examine this myself. In particular, both problems
 (the already-unified `kappa` and the `F Int` example) would seem to be
 solved as long as we flatten kinds sufficiently. I have reworked some of
 the code around this in Phab:D3848 (my big flattener patch), which is
 currently (with much progress made today) undergoing revisions as
 suggested last week. This new version explicitly flattens kinds before
 emitting the derived, and so I wonder if your test program behaves
 differently on my end.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11198#comment:19>
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