[GHC] #15368: Type families, holes and -fdefer-type-errors may cause 'opt_univ fell into a hole' panic

[GHC]

#15368: Type families, holes and -fdefer-type-errors may cause 'opt_univ fell into
a hole' panic
-------------------------------------+-------------------------------------
        Reporter:  dramforever       |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:  8.8.1
       Component:  Compiler          |              Version:  8.4.3
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  Compile-time      |            Test Case:
  crash or panic                     |  typecheck/should_compile/T15368
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
-------------------------------------+-------------------------------------

Comment (by Krzysztof Gogolewski <krz.gogolewski@…>):

 In [changeset:"49d50b2b7d194dca0b23de6fe4dcc717562e90a7/ghc"
 49d50b2b/ghc]:
 {{{
 #!CommitTicketReference repository="ghc"
 revision="49d50b2b7d194dca0b23de6fe4dcc717562e90a7"
 testsuite: Add test for #15368

 Reviewers: bgamari, osa1

 Reviewed By: osa1

 Subscribers: osa1, monoidal, rwbarton, thomie, carter

 GHC Trac Issues: #15368

 Differential Revision: https://phabricator.haskell.org/D4958
 }}}

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/15368#comment:6>
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