[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:  patch
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  8.2.1
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  Compile-time      |  Unknown/Multiple
  crash or panic                     |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):  Phab:D4132
       Wiki Page:                    |
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Comment (by Ben Gamari <ben@…>):

 In [changeset:"85aa1f4253163985fe07d172f8da73b784bb7b4b/ghc"
 85aa1f42/ghc]:
 {{{
 #!CommitTicketReference repository="ghc"
 revision="85aa1f4253163985fe07d172f8da73b784bb7b4b"
 Fix #14390 by making toIfaceTyCon aware of equality

 GHC was panicking when pretty-printing a heterogeneous
 equality type constructor (#14390) because the function which
 produced the type constructor, `toIfaceTyCon`, wasn't attaching the
 appropriate `IfaceTyConSort` for equality type constructors, which
 is `IfaceEqualityTyCon`. This is fixed easily enough.

 Test Plan: make test TEST=T14390

 Reviewers: austin, bgamari

 Reviewed By: bgamari

 Subscribers: rwbarton, thomie

 GHC Trac Issues: #14390

 Differential Revision: https://phabricator.haskell.org/D4132
 }}}

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14390#comment:3>
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