[GHC] #14390: Panic when defining an instance for (~~) [ppr_equality: homogeneity]

[GHC]

#14390: Panic when defining an instance for (~~) [ppr_equality: homogeneity]
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        Reporter:  RyanGlScott       |                Owner:  (none)
            Type:  bug               |               Status:  closed
        Priority:  normal            |            Milestone:  8.4.1
       Component:  Compiler          |              Version:  8.2.1
      Resolution:  fixed             |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  Compile-time      |  Unknown/Multiple
  crash or panic                     |            Test Case:  T14390
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):  Phab:D4132
       Wiki Page:                    |
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Comment (by Simon Peyton Jones <simonpj@…>):

 In [changeset:"29ae83374647e227d76acd896b89590fc15590d6/ghc" 29ae833/ghc]:
 {{{
 #!CommitTicketReference repository="ghc"
 revision="29ae83374647e227d76acd896b89590fc15590d6"
 Tidy up IfaceEqualityTyCon

 This commit

   commit 85aa1f4253163985fe07d172f8da73b784bb7b4b
   Date:   Sun Oct 29 20:48:19 2017 -0400
     Fix #14390 by making toIfaceTyCon aware of equality

 was a bit over-complicated. This patch simplifies the (horribly
 ad-hoc) treatement of IfaceEqualityTyCon, and documents it better.

 No visible change in behaviour.
 }}}

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14390#comment:6>
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