Bug in last CVS

I have a bug in a CVS version for MacOSX from tuesday:

While compiling last version of Frantk:

Compiling DisplaySimple    ( FranTkSrc/DisplaySimple.lhs,
FranTkSrc/DisplaySimple.o )
ghc-5.05: panic! (the `impossible' happened, GHC version 5.05):
        rename/RnExpr.lhs:164: Non-exhaustive patterns in function rnExpr


Please report it as a compiler bug to glasgow-haskell-bugs@xxxxxxxxxxx,
or http://sourceforge.net/projects/ghc/.

Best regards,
Nicolas Oury