Encountered absent arg

[Max Bolingbroke]

On 7 April 2010 00:23, Louis Wasserman <wasserman.louis at gmail.com> wrote:
> biggest sources of angst!)  Looking at ghc-core, my code appears to
> always give the exception "Oops!  Entered absent arg ww_s9eC{v} [lid]
> <pred>main:Data.Algebra.Ring.Ring{tc r2tU} c{tv a8Os} [tv]"
> Is this typical?  Where should I send this?

This is certainly a bug. Is it possible to extract a minimal test
case, and post it on the GHC Trac
(http://hackage.haskell.org/trac/ghc/)?

Cheers,
Max