Determine the version of sed based on the output of "--version" rather than ${OSTYPE}. The later approach is not reliable when an user installed GNU sed in Darwin systems like macOS.

tensorflower-gardener · tensorflower-gardener · commit 14221c1fd415 · 2017-05-11T18:14:01.000-07:00
PiperOrigin-RevId: 155822030
diff --git a/tensorflow/contrib/makefile/download_dependencies.sh b/tensorflow/contrib/makefile/download_dependencies.sh
@@ -30,9 +30,13 @@ RE2_URL="$(grep -o 'http.*github.com/google/re2/.*tar\.gz' "${BZL_FILE_PATH}" |
 replace_by_sed() {
   local regex="${1}"
   shift
-  if echo "${OSTYPE}" | grep -q darwin; then
+  # Detect the version of sed by the return value of "--version" flag. GNU-sed
+  # supports "--version" while BSD-sed doesn't.
+  if ! sed --version >/dev/null 2>&1; then
+    # BSD-sed.
     sed -i '' -e "${regex}" "$@"
   else
+    # GNU-sed.
     sed -i -e "${regex}" "$@"
   fi
 }
