Use cp -a instead of cp -ar.

ports/vim/build.sh

 # Copyright (c) 2013 The Native Client Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 BUILD_DIR=${SRC_DIR}
 EXTRA_CONFIGURE_ARGS+="--enable-gui=no --with-tlib=ncurses"
 EXTRA_CONFIGURE_ARGS+=" --prefix=/usr --exec-prefix=/usr"
 EXECUTABLES=src/vim${NACL_EXEEXT}
 export EXTRA_LIBS="${NACL_CLI_MAIN_LIB}"
 
@@ skipping 28 matching lines @@
   DefaultInstallStep
   LogExecute mv ${INSTALL_DIR}/usr ${INSTALL_DIR}${PREFIX}
 }
 
 PublishStep() {
   MakeDir ${PUBLISH_DIR}
   local ASSEMBLY_DIR="${PUBLISH_DIR}/vim"
 
   MakeDir ${ASSEMBLY_DIR}/vimtar/usr
   ChangeDir ${ASSEMBLY_DIR}/vimtar
-  LogExecute cp -ar ${INSTALL_DIR}${PREFIX}/* ./usr/
+  LogExecute cp -a ${INSTALL_DIR}${PREFIX}/* ./usr/
   LogExecute cp usr/bin/vim${NACL_EXEEXT} ../vim_${NACL_ARCH}${NACL_EXEEXT}
   LogExecute cp $SRC_DIR/runtime/vimrc_example.vim usr/share/vim/vimrc
   LogExecute rm -rf usr/bin
   LogExecute rm -rf usr/share/man
   tar cf ${ASSEMBLY_DIR}/vim.tar .
   Remove ${ASSEMBLY_DIR}/vimtar
   shasum ${ASSEMBLY_DIR}/vim.tar > ${ASSEMBLY_DIR}/vim.tar.hash
   cd ${ASSEMBLY_DIR}
   LogExecute python ${NACL_SDK_ROOT}/tools/create_nmf.py \
       vim_*${NACL_EXEEXT} \
       -s . \
       -o vim.nmf
   LogExecute python ${TOOLS_DIR}/create_term.py vim.nmf
 
   GenerateManifest ${START_DIR}/manifest.json ${ASSEMBLY_DIR}
   InstallNaClTerm ${ASSEMBLY_DIR}
   LogExecute cp ${START_DIR}/background.js ${ASSEMBLY_DIR}
   LogExecute cp ${START_DIR}/vim.html ${ASSEMBLY_DIR}
   LogExecute cp ${START_DIR}/vim_app.html ${ASSEMBLY_DIR}
   LogExecute cp ${START_DIR}/vim.js ${ASSEMBLY_DIR}
   LogExecute cp ${START_DIR}/icon_16.png ${ASSEMBLY_DIR}
   LogExecute cp ${START_DIR}/icon_48.png ${ASSEMBLY_DIR}
   LogExecute cp ${START_DIR}/icon_128.png ${ASSEMBLY_DIR}
   ChangeDir ${PUBLISH_DIR}
   CreateWebStoreZip vim-${VERSION}.zip vim
 }