HEAD: the `impossible' happened, MacOS X

This is yesterdays HEAD:

../../ghc/compiler/ghc-inplace -H32m -O0 -W -fno-warn-unused-matches 
-fwarn-unused-imports -L/sw/lib -fglasgow-exts -cpp -Iinclude -#include 
HsBase.h -funbox-strict-fields -package-name base -dcore-lint -W 
-fno-warn-unused-matches -fwarn-unused-imports -keep-hc-files      -c 
System/Random.hs -o System/Random.o  -ohi System/Random.hi

System/Random.hs:15:
    Warning: Module `GHC.IOBase' is imported, but nothing from it is used
             (except perhaps instances visible in `GHC.IOBase')
ghc-5.05: panic! (the `impossible' happened, GHC version 5.05):
        ASSERT failed! file stgSyn/CoreToStg.lhs line 188
randomIvalDouble1 {- v s2Im -}
-- 
Volker Stolz * http://www-i2.informatik.rwth-aachen.de/stolz/ * PGP * S/MIME