Don't package OSX's magic ._foo files

build_tools/common.sh

Index: build_tools/common.sh
diff --git a/build_tools/common.sh b/build_tools/common.sh
index 4527f7083e3828fadbffb111767f0f5236e96ce9..f37a66a9fe80b408d6f09a4b4767f060d074b1d9 100644
--- a/build_tools/common.sh
+++ b/build_tools/common.sh
@@ -1513,7 +1513,14 @@ PackageStep() {
   echo "BUILD_TOOLCHAIN=${TOOLCHAIN}" >> "${INSTALL_DIR}/pkg_info"
   echo "BUILD_SDK_VERSION=${NACL_SDK_VERSION}" >> "${INSTALL_DIR}/pkg_info"
   echo "BUILD_NACLPORTS_REVISION=${FULL_REVISION}" >> "${INSTALL_DIR}/pkg_info"
-  LogExecute tar cjf "${PACKAGE_FILE}" -C "${INSTALL_DIR}" .
+  if [ "${OS_NAME}" = "Darwin" ]; then
+    # OSX likes to create files starting with ._. We don't want to package
+    # these.
+    local args="--exclude ._*"
+  else
+    local args=""
+  fi
+  LogExecute tar cjf "${PACKAGE_FILE}" -C "${INSTALL_DIR}" ${args} .
 }