[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):

 This patch
 {{{
 commit 4de4b2253caa685a39cc654d553cdf63b8babbee
 Author: Simon Peyton Jones <simonpj at microsoft.com>
 Date:   Thu Oct 25 15:16:19 2018 +0100

     Fix generalisation for type constructors

     Fixing the way that we close-over-kinds when taking the
     free vars of a type revealed that the way we generalise
     type constructors was a bit wrong.

     This fixes it.  See TcTyClDecls
     Note [Generalisation for type constructors]


 >---------------------------------------------------------------

 4de4b2253caa685a39cc654d553cdf63b8babbee
  compiler/typecheck/TcTyClsDecls.hs | 58 +++++++++++++++++++++---
  compiler/typecheck/TcValidity.hs   | 92
 +++++++++++++++-----------------------
  2 files changed, 86 insertions(+), 64 deletions(-)
 }}}
 turned out to be necessary as a precursor to the patch in comment:153.
 The lack of it was the reason for the two validation failures mentioned in
 comment:152.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14880#comment:155>
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