panic! (the 'impossible' happened) ... splitFunTy ...

"MyModule.hs" containing these four lines:

module MyModule where
data T a = CT {f1 :: Int -> a, f2 :: Double}
f2 :: Int -> Double
g x = CT {f1 = \t -> f2 t + x, f2 = x}

yields:

C:\Tasks\Task_IsolateGhcBug>ghc --make MyModule.hs -v
Glasgow Haskell Compiler, Version 7.0.3, for Haskell 98, stage 2 booted by GHC version 6.12.2
Using binary package database: C:\Programme\Haskell Platform\2011.2.0.1\lib\package.conf.d\package.cache
wired-in package ghc-prim mapped to ghc-prim-0.2.0.0-e1f7c380581d61d42b0360d440cc35ed
wired-in package integer-gmp mapped to integer-gmp-0.2.0.3-91607778cf3ae8f3948a50062b4f8479
wired-in package base mapped to base-4.3.1.0-f520cd232cc386346843c4a12b63f44b
wired-in package rts mapped to builtin_rts
wired-in package template-haskell mapped to template-haskell-2.5.0.0-7d9b1443ac5ab69e5ed705a487990deb
wired-in package dph-seq not found.
wired-in package dph-par not found.
Hsc static flags: -static
*** Chasing dependencies:
Chasing modules from: *MyModule.hs
Stable obj: []
Stable BCO: []
Ready for upsweep
  [NONREC
      ModSummary {
         ms_hs_date = Thu Oct  6 19:01:55 Westeuropäische Sommerzeit 2011
         ms_mod = main:MyModule,
         ms_imps = [import Prelude]
         ms_srcimps = []
      }]
compile: input file MyModule.hs
Created temporary directory: C:\Temp\ghc4956_0
*** Checking old interface for main:MyModule:
[1 of 1] Compiling MyModule         ( MyModule.hs, MyModule.o )
*** Parser:
*** Renamer/typechecker:
*** Desugar:
*** Deleting temp files:
Deleting: C:\Temp\ghc4956_0\ghc4956_0.s
Warning: deleting non-existent C:\Temp\ghc4956_0\ghc4956_0.s
*** Deleting temp dirs:
Deleting: C:\Temp\ghc4956_0
ghc: panic! (the 'impossible' happened)
  (GHC version 7.0.3 for i386-unknown-mingw32):
        splitFunTy
    forall a{tv aby} [tv].
    main:MyModule.T{tc rbp} a{tv aby} [tv]
    -> ghc-prim:GHC.Types.Double{(w) tc 3u}

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

Trac metadata

Trac field	Value
Version	7.0.3
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Compiler
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