[GHC] #14880: GHC panic: updateRole

[GHC]

#14880: GHC panic: updateRole
-------------------------------------+-------------------------------------
        Reporter:  RyanGlScott       |                Owner:  goldfire
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:  8.6.2
       Component:  Compiler (Type    |              Version:  8.2.2
  checker)                           |
      Resolution:                    |             Keywords:  TypeInType
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  Compile-time      |  Unknown/Multiple
  crash or panic                     |            Test Case:
      Blocked By:                    |             Blocking:  15592
 Related Tickets:  #15076            |  Differential Rev(s):  Phab:D4769,
                                     |  Phab:D5141, Phab:D5147, Phab:D5150,
       Wiki Page:                    |  Phab:D5208
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Comment (by simonpj):

 > Looks like ​Phab:D5141 validates cleanly. Do we still need this part, or
 does ​Phab:D5208 supersede this effort?

 No, it doesn't supersede.  Let's just get D5141 committed. It does Step 1.
 Then we can at last forget about Step 1.

 In fact, let's do Step 2 too.  All we need to do there is to deal with the
 `closeOverKinds` change, using the clever trick in comment:123.   '''But
 NB: you need the same trick for `ty_co_vars_of_co_var`.

 I think Step 2 should work cleanly, and probably improves performance.
 Tobias can you do that?

 That sets the stage for Phab:D5208, where some semantic trickiness is
 going on.  But let's get the easy stuff done, nailed, committed, and
 forgotten!

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14880#comment:149>
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