Try to track down mac ld issue

tools/clang/scripts/update.sh

 #!/bin/bash
 # Copyright (c) 2011 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 # This script will check out llvm and clang into third_party/llvm and build it.
 
 THIS_DIR="$(dirname "${0}")"
 LLVM_DIR="${THIS_DIR}/../../../third_party/llvm"
 LLVM_BUILD_DIR="${LLVM_DIR}/../llvm-build"
@@ skipping 62 matching lines @@
   echo Getting clang r"${CLANG_REVISION}" in "${CLANG_DIR}"
   svn co --force "${LLVM_REPO_URL}/cfe/trunk@${CLANG_REVISION}" "${CLANG_DIR}"
 fi
 
 # Echo all commands.
 set -x
 
 # Build clang (in a separate directory).
 # The clang bots have this path hardcoded in built/scripts/slave/compile.py,
 # so if you change it you also need to change these links.
+rm -rf "${LLVM_BUILD_DIR}"  # clobber (XXX temporary don't check in)
 mkdir -p "${LLVM_BUILD_DIR}"
 cd "${LLVM_BUILD_DIR}"
 if [ ! -f ./config.status ]; then
   ../llvm/configure \
       --enable-optimized \
       --disable-threads \
       --disable-pthreads \
       --without-llvmgcc \
       --without-llvmgxx
 fi
@@ skipping 15 matching lines @@
 PLUGIN_BUILD_DIR="${LLVM_BUILD_DIR}/tools/clang/tools/chrome-plugin"
 rm -rf "${PLUGIN_DST_DIR}"
 cp -R "${PLUGIN_SRC_DIR}" "${PLUGIN_DST_DIR}"
 rm -rf "${PLUGIN_BUILD_DIR}"
 mkdir -p "${PLUGIN_BUILD_DIR}"
 cp "${PLUGIN_SRC_DIR}/Makefile" "${PLUGIN_BUILD_DIR}"
 make -j"${NUM_JOBS}" -C "${PLUGIN_BUILD_DIR}"
 
 # After everything is done, log success for this revision.
 echo "${CLANG_REVISION}" > "${STAMP_FILE}"