[GHC] #13780: Nightmarish pretty-printing of equality type in GHC 8.2 error message

[GHC]

#13780: Nightmarish pretty-printing of equality type in GHC 8.2 error message
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        Reporter:  RyanGlScott       |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler (Type    |              Version:  8.2.1-rc2
  checker)                           |
      Resolution:                    |             Keywords:  TypeInType
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  Poor/confusing    |  Unknown/Multiple
  error message                      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Changes (by RyanGlScott):

 * cc: simonpj (added)


Comment:

 This was caused by either commit 77bb09270c70455bbd547470c4e995707d19f37d
 ( Re-add FunTy (big patch)) or e368f3265b80aeb337fbac3f6a70ee54ab14edfd
 (Major patch to introduce TyConBinder). I can't know for sure since commit
 77bb09270c70455bbd547470c4e995707d19f37d doesn't build properly.

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13780#comment:1>
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