Compiling HTTP-4000.0.4 makes GHC 6.11.20090121 panic

[wolverian]

Compiling Network.HTTP.MD5Aux makes GHC HEAD panic:

[wolverian@noesis lambdabot]$ cabal install
Resolving dependencies...
'HTTP-4000.0.4' is cached.
Configuring HTTP-4000.0.4...
Preprocessing library HTTP-4000.0.4...
Building HTTP-4000.0.4...
[ 1 of 15] Compiling Network.HTTP.Utils ( Network/HTTP/Utils.hs, dist/build/Network/HTTP/Utils.o )
[ 2 of 15] Compiling Network.HTTP.MD5Aux ( Network/HTTP/MD5Aux.hs, dist/build/Network/HTTP/MD5Aux.o )
ghc: panic! (the 'impossible' happened)
  (GHC version 6.11.20090121 for x86_64-unknown-linux):
        srtExpr
    \ [m{v s2Li} [lid]] ->
    case
        <=#{v} [m{v s2Li} [lid] 1] :: Alg ghc-prim:GHC.Bool.Bool{(w) tc 3c}
    of
    wild2{v s3X3} [lid]
    {   -- lvs: [n1{v s2Lg} [lid]
                 m{v s2Li} [lid]
                 xs1{v s2Lk} [lid]
                 lvl21{v s2Ln} [lid]]; rhs lvs: [n1{v s2Lg} [lid]
                                                 m{v s2Li} [lid]
                                                 xs1{v s2Lk} [lid]
                                                 lvl21{v s2Ln} [lid]]; srt:SRT:[]
      ghc-prim:GHC.Bool.False{(w) d 68} ->
          let {
            sat_s3X5{v} [lid] =
                [m{v s2Li} [lid] xs1{v s2Lk} [lid]] \u srt:SRT:[] []
                    case
                        -#{v} [m{v s2Li} [lid] 1] :: Prim ghc-prim:GHC.Prim.Int#{(w) tc 3G}
                    of
                    sat_s3X4{v} [lid]
                    {   -- lvs: [m{v s2Li} [lid]
                                 xs1{v s2Lk} [lid]]; rhs lvs: [xs1{v s2Lk} [lid]]; srt:SRT:[]
                      __DEFAULT -> xs1{v s2Lk} [lid] sat_s3X4{v} [lid];
                    };
          } in 
            ghc-prim:GHC.Types.:{(w) d 64} [lit1{v r2vA} [gid]
                                            sat_s3X5{v} [lid]];
      ghc-prim:GHC.Bool.True{(w) d 6u} -> lvl21{v s2Ln} [lid];
    }

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

[simonpj]

Urk. Thanks for finding this. I've fixed it now:

Thu Jan 29 05:19:54 PST 2009  simonpj@microsoft.com
  * Two more wibbles to CorePrep (fixes HTTP package and DPH)

Simon