[GHC] #15859: Dependent quantification, GHC panic

[GHC]

#15859: Dependent quantification, GHC panic
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        Reporter:  Iceland_jack      |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  8.6.1
      Resolution:                    |             Keywords:  TypeInType
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by Richard Eisenberg <rae@…>):

 In [changeset:"72b82343b79365dc74ffafb345dd33499a7fd394/ghc"
 72b82343/ghc]:
 {{{
 #!CommitTicketReference repository="ghc"
 revision="72b82343b79365dc74ffafb345dd33499a7fd394"
 Fix #15859 by checking, not assuming, an ArgFlag

 We thought that visible dependent quantification was impossible
 in terms, but Iceland Jack discovered otherwise in #15859. This fixes an
 ASSERT failure that arose.

 test case: dependent/should_fail/T15859
 }}}

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/15859#comment:2>
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