HEAD doesn't not build on OS X

[Johan Tibell]

While trying to build head (from a maintainer-clean tree) I get the
following error:

echo "compiler_stage1_depfile_haskell_EXISTS = YES" >>
compiler/stage1/build/.depend-v.haskell.tmp
for dir in compiler/stage1/build/./ compiler/stage1/build/Llvm/
compiler/stage1/build/LlvmCodeGen/ compiler/stage1/build/PPC/
compiler/stage1/build/RegAlloc/ compiler/stage1/build/RegAlloc/Graph/
compiler/stage1/build/RegAlloc/Linear/
compiler/stage1/build/RegAlloc/Linear/PPC/
compiler/stage1/build/RegAlloc/Linear/SPARC/
compiler/stage1/build/RegAlloc/Linear/X86/
compiler/stage1/build/SPARC/ compiler/stage1/build/SPARC/CodeGen/
compiler/stage1/build/Vectorise/
compiler/stage1/build/Vectorise/Builtins/
compiler/stage1/build/Vectorise/Monad/
compiler/stage1/build/Vectorise/Type/
compiler/stage1/build/Vectorise/Utils/ compiler/stage1/build/X86/; do
if test ! -d $dir; then mkdir -p $dir; fi done
grep -v ' : [a-zA-Z]:/' compiler/stage1/build/.depend-v.haskell.tmp >
compiler/stage1/build/.depend-v.haskell
"/usr/sbin/dtrace" -Iincludes -Irts -Ilibffi/build/include -C -x
cpppath=/usr/bin/gcc -h -o rts/dist/build/RtsProbes.h -s
rts/RtsProbes.d
. includes/HsFFI.h
.. includes/ghcconfig.h
... includes/ghcautoconf.h
... includes/ghcplatform.h
.. includes/stg/Types.h
.. /usr/lib/gcc/i686-apple-darwin10/4.2.1/include/stdint.h
.. /usr/lib/gcc/i686-apple-darwin10/4.2.1/include/float.h
. includes/rts/EventLogFormat.h
dtrace: failed to compile script rts/RtsProbes.d: line 71: parameter
is already declared in probe input prototype: StgWord, parameter #6
make[1]: *** [rts/dist/build/RtsProbes.h] Error 1
make: *** [all] Error 2