[GHC] #11819: Full validation issues for 8.0.1

[GHC]

#11819: Full validation issues for 8.0.1
-------------------------------------+-------------------------------------
        Reporter:  bgamari           |                Owner:
            Type:  bug               |               Status:  new
        Priority:  high              |            Milestone:  8.0.2
       Component:  Compiler          |              Version:  8.0.1-rc3
      Resolution:                    |             Keywords:
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 niteria):

 7afb7adf45216701e4f645676ecc0668f64b424d fixes the in-scope set failure on
 `PatBind`:
 {{{
 ghc-stage2: panic! (the 'impossible' happened)
   (GHC version 8.0.1.20160916 for x86_64-unknown-linux):
         ASSERT failed!
   CallStack (from HasCallStack):
   assertPprPanic, called at compiler/types/TyCoRep.hs:2008:56 in
 ghc:TyCoRep
   checkValidSubst, called at compiler/types/TyCoRep.hs:2044:17 in
 ghc:TyCoRep
   substTy, called at compiler/types/TyCoRep.hs:1986:3 in ghc:TyCoRep
   in_scope InScope [apd :-> a_apd[sk], apm :-> a_apm[tau:3],
                     apn :-> t_apn[tau:3]]
   tenv [ap4 :-> t_apn[tau:3], apd :-> a_apm[tau:3]]
   tenvFVs [ap5 :-> t_ap5[tau:3], apm :-> a_apm[tau:3],
            apn :-> t_apn[tau:3]]
   cenv []
   cenvFVs []
   tys [a_apd[sk] -> a_apd[sk]]
   cos []

 Please report this as a GHC bug:  http://www.haskell.org/ghc/reportabug


 *** unexpected failure for PatBind(normal)
 }}}

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11819#comment:3>
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