ghci crashes

Given the two attached files, HLint.hs and System.Console.CmdArgs.hs, if I do:

$ ghc --version
The Glorious Glasgow Haskell Compilation System, version 6.10.3.20090530
$ runhaskell HLint.hs helm

Then GHC segfaults. This is on Windows Vista.

I looked in to reducing this bug, and totally failed. If I modify a single line, even totally unconnected, then it works. If I reduce any single output string in the program by even 1 character, it then starts working. I suspect there is a off-by-one error at some boundary condition, so while the error is 100% repeatable, it doesn't look like an easy one to debug.

I suspect that something trivial like a change in the desugaring of any construct will stop this bug happening with this particular file. However, I suspect that just means the bug moves to a different magic constant and will still be there underneath.

Trac metadata

Trac field	Value
Version	6.10.4
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Compiler
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