[GHC] #13959: substTyVar's definition is highly dubious

[GHC]

#13959: substTyVar's definition is highly dubious
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        Reporter:  RyanGlScott       |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  8.0.1
      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 goldfire):

 comment:3 is easy to diagnose: note that the stack includes
 `substCoWithUnchecked`, but the "uncheckedness" doesn't propagate. Not
 sure what the best way to fix this is, but the underlying problem is not
 ours.

 comment:2 is as you describe: the `inst_tvs` here do ''not'' need to
 contain the kinds. But the `InScopeSet` surely does! Use `closeOverKinds`.
 This is a latent bug, as I expected.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13959#comment:4>
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