GHC 5.05 panic in speceval_2 branch

I was trying to compile GHC from the CVS sources in the speceval_2 
branch.  I am reporting this error out of sheer obedience ;-)

So I guess there are some tricks required to compile this branch.

--Andreas

BEGIN OUTPUT

------------------------------------------------------------------------
==fptools== make all -wr;
 in /home/abel/cover/speceval_2/build/libraries/base
------------------------------------------------------------------------
../../ghc/compiler/ghc-inplace -H32m -O0 -W -fno-warn-unused-matches 
-fwarn-unused-imports -lbfd -liberty -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 
GHC/Base.lhs -o GHC/Base.o  -ohi GHC/Base.hi
NOTE: Simplifier still going after 4 iterations; bailing out.
nukeVolatileBinds: strange unpack{-s1UL*-}
nukeVolatileBinds: strange unpack{-s1UL*-}
nukeVolatileBinds: strange unpack{-s1UL*-}
nukeVolatileBinds: strange unpack{-s1UL*-}
nukeVolatileBinds: strange unpack{-s1XE*-}
nukeVolatileBinds: strange unpack{-s1XX*-}
nukeVolatileBinds: strange ys{-s25B*-}
nukeVolatileBinds: strange unpack{-s28W*-}
nukeVolatileBinds: strange ys{-s2ab*-}
nukeVolatileBinds: strange xs{-s2at*-}
nukeVolatileBinds: strange xs{-s2aE*-}
nukeVolatileBinds: strange ys{-s2aX*-}
nukeVolatileBinds: strange ys{-s2bd*-}
ghc-5.05: panic! (the `impossible' happened, GHC version 5.05):
        Optimistic Evaluation does not currently support native code 
generation
    Use -fvia-C or -O

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


make[2]: *** [GHC/Base.o] Error 1
make[1]: *** [all] Error 1
make[1]: Leaving directory `/home/abel/cover/speceval_2/build/libraries'
make: *** [build] Error 1

END OUTPUT