[GHC] #15290: QuantifiedConstraints: panic "addTcEvBind NoEvBindsVar"

[GHC]

#15290: QuantifiedConstraints: panic "addTcEvBind NoEvBindsVar"
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        Reporter:  goldfire          |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:  8.6.1
       Component:  Compiler          |              Version:  8.4.3
      Resolution:                    |             Keywords:
                                     |  QuantifiedConstraints
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:  quantified-
                                     |  constraints/T15290, T15290a
      Blocked By:                    |             Blocking:  9123, 14883
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by simonpj):

 > On the subject of the actual panic observed in this ticket, I don't
 think Simon's commit quite fixed it. I'm still observing the panic on
 commit 122ba98af22c2b016561433dfa55bbabba98d972 with this program (taken
 from #14883):

 Are you sure?  It compiles on HEAD for me.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/15290#comment:28>
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