-prof build: trying to 'show' a 'Double' leads to 'Char.intToDigit: not a digit' crash

The source is very simple:

main :: IO ()
main = putStrLn $ show (1 :: Double)

Run as:

ghc --make double.hs -prof -fforce-recomp -o double.buggy && ./double.buggy

Dies as:

[1 of 1] Compiling Main ( 144.hs, 144.o )

Linking double.buggy ...

double.buggy: Char.intToDigit: not a digit 7488688

It's an amd64 gentoo linux with **gcc-4.7.2**. Core i7 system with avx support.

If I drop **-prof** the bug goes away. If I change **Double** to **Float**, **Int**, **Integer** the bug goes away.

I might have miscompiled RTS or something. Which is the best way to verify?

 [("Project name","The Glorious Glasgow Haskell Compilation System")
 ,("GCC extra via C opts"," -fwrapv")
 ,("C compiler command","x86_64-pc-linux-gnu-gcc")
 ,("C compiler flags"," -fno-stack-protector  -Wl,--hash-size=31 -Wl,--reduce-memory-overheads")
 ,("ar command","/usr/bin/ar")
 ,("ar flags","q")
 ,("ar supports at file","YES")
 ,("touch command","touch")
 ,("dllwrap command","/bin/false")
 ,("windres command","/bin/false")
 ,("perl command","/usr/bin/perl")
 ,("target os","OSLinux")
 ,("target arch","ArchX86_64")
 ,("target word size","8")
 ,("target has GNU nonexec stack","True")
 ,("target has .ident directive","True")
 ,("target has subsections via symbols","False")
 ,("LLVM llc command","/usr/bin/llc")
 ,("LLVM opt command","/usr/bin/opt")
 ,("Project version","7.6.2")
 ,("Booter version","7.6.2")
 ,("Stage","2")
 ,("Build platform","x86_64-unknown-linux")
 ,("Host platform","x86_64-unknown-linux")
 ,("Target platform","x86_64-unknown-linux")
 ,("Have interpreter","YES")
 ,("Object splitting supported","YES")
 ,("Have native code generator","YES")
 ,("Support SMP","YES")
 ,("Unregisterised","NO")
 ,("Tables next to code","YES")
 ,("RTS ways","l debug  thr thr_debug thr_l thr_p dyn debug_dyn thr_dyn thr_debug_dyn")
 ,("Leading underscore","NO")
 ,("Debug on","False")
 ,("LibDir","/usr/lib64/ghc-7.6.2")
 ,("Global Package DB","/usr/lib64/ghc-7.6.2/package.conf.d")
 ,("Gcc Linker flags","[\"-Wl,--hash-size=31\",\"-Wl,--reduce-memory-overheads\"]")
 ,("Ld Linker flags","[\"--hash-size=31\",\"--reduce-memory-overheads\"]")
 ]

Trac metadata

Trac field	Value
Version	7.6.2
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Compiler
Test case
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