[GHC] #5668: panic: updInertSet

[GHC]

#5668: panic: updInertSet
---------------------------------+------------------------------------------
    Reporter:  simonmar          |        Owner:                    
        Type:  bug               |       Status:  new               
    Priority:  highest           |    Milestone:  7.4.1             
   Component:  Compiler          |      Version:  7.2.1             
    Keywords:                    |     Testcase:                    
   Blockedby:                    |   Difficulty:                    
          Os:  Unknown/Multiple  |     Blocking:                    
Architecture:  Unknown/Multiple  |      Failure:  Compile-time crash
---------------------------------+------------------------------------------
 Building `parsec-3.1.2` with HEAD panics with a complaint about
 `updInertSet`.

 {{{
 Building parsec-3.1.2...
 [ 1 of 25] Compiling Text.Parsec.Pos  ( Text/Parsec/Pos.hs,
 dist/build/Text/Parsec/Pos.o )
 [ 2 of 25] Compiling Text.Parsec.Error ( Text/Parsec/Error.hs,
 dist/build/Text/Parsec/Error.o )
 [ 3 of 25] Compiling Text.ParserCombinators.Parsec.Error (
 Text/ParserCombinators/Parsec/Error.hs,
 dist/build/Text/ParserCombinators/Parsec/Error.o )
 [ 4 of 25] Compiling Text.ParserCombinators.Parsec.Pos (
 Text/ParserCombinators/Parsec/Pos.hs,
 dist/build/Text/ParserCombinators/Parsec/Pos.o )
 [ 5 of 25] Compiling Text.Parsec.Prim ( Text/Parsec/Prim.hs,
 dist/build/Text/Parsec/Prim.o )
 ghc-stage2: panic! (the 'impossible' happened)
   (GHC version 7.3.20111129 for x86_64-unknown-linux):
         updInertSet
     Multiple inert equalities:
     Old (already inert): ([W]{0} ( cobox{v a5FZ} [lid] :: ( m_ta4{tv}
 [tau] :: ghc-prim:GHC.Prim.*{(w) tc 34d}
 -> ghc-prim:GHC.Prim.*{(w) tc 34d} )
                                                           ghc-
 prim:GHC.Types.~{(w) tc 31Q} ( m{tv a5Fj} [sk] :: ghc-prim:GHC.Prim.*{(w)
 tc 34d}
 -> ghc-prim:GHC.Prim.*{(w) tc 34d} ) ) :: ( m_ta4{tv} [tau] :: ghc-
 prim:GHC.Prim.*{(w) tc 34d}
 -> ghc-prim:GHC.Prim.*{(w) tc 34d} )
 ghc-prim:GHC.Types.~{(w) tc 31Q} ( m{tv a5Fj} [sk] :: ghc-
 prim:GHC.Prim.*{(w) tc 34d}
 -> ghc-prim:GHC.Prim.*{(w) tc 34d} ) (CTyEqCan),
                           ( cobox{v a5FZ} [lid] :: ( m_ta4{tv} [tau] ::
 ghc-prim:GHC.Prim.*{(w) tc 34d}
                                                                         ->
 ghc-prim:GHC.Prim.*{(w) tc 34d} )
                                                    ghc-
 prim:GHC.Types.~{(w) tc 31Q} ( m{tv a5Fj} [sk] :: ghc-prim:GHC.Prim.*{(w)
 tc 34d}
 -> ghc-prim:GHC.Prim.*{(w) tc 34d} ) ))
     Trying to insert   : ([W]{0} ( cobox{v a5FZ} [lid] :: ( m_ta4{tv}
 [tau] :: ghc-prim:GHC.Prim.*{(w) tc 34d}
 -> ghc-prim:GHC.Prim.*{(w) tc 34d} )
                                                           ghc-
 prim:GHC.Types.~{(w) tc 31Q} ( m{tv a5Fj} [sk] :: ghc-prim:GHC.Prim.*{(w)
 tc 34d}
 -> ghc-prim:GHC.Prim.*{(w) tc 34d} ) ) :: ( m_ta4{tv} [tau] :: ghc-
 prim:GHC.Prim.*{(w) tc 34d}
 -> ghc-prim:GHC.Prim.*{(w) tc 34d} )
 ghc-prim:GHC.Types.~{(w) tc 31Q} ( m{tv a5Fj} [sk] :: ghc-
 prim:GHC.Prim.*{(w) tc 34d}
 -> ghc-prim:GHC.Prim.*{(w) tc 34d} ) (CTyEqCan),
                           ( cobox{v a5FZ} [lid] :: ( m_ta4{tv} [tau] ::
 ghc-prim:GHC.Prim.*{(w) tc 34d}
                                                                         ->
 ghc-prim:GHC.Prim.*{(w) tc 34d} )
                                                    ghc-
 prim:GHC.Types.~{(w) tc 31Q} ( m{tv a5Fj} [sk] :: ghc-prim:GHC.Prim.*{(w)
 tc 34d}
 -> ghc-prim:GHC.Prim.*{(w) tc 34d} ) ))

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


 To repeat:

 {{{
 $ cabal install --with-ghc=$ghcval parsec
 }}}

 where `$ghcval` is your GHC.  In this case it was a GHC I had just built
 with `validate`, I wanted to install `parsec` so I could test something
 else.

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/5668>
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