api: require python3 in more modules
These are all used by python3-only code, so mark them as such to
avoid possible regressions.
BUG=chromium:997354
TEST=`./run_tests` passes
Change-Id: Ie68bca9dae9cf5dd213d3857d1856ee8895605a4
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/chromite/+/2154061
Reviewed-by: Alex Klein <saklein@chromium.org>
Commit-Queue: Mike Frysinger <vapier@chromium.org>
Tested-by: Mike Frysinger <vapier@chromium.org>
diff --git a/api/message_util.py b/api/message_util.py
index a72a1dc..684348f 100644
--- a/api/message_util.py
+++ b/api/message_util.py
@@ -16,11 +16,16 @@
from __future__ import print_function
import os
+import sys
from google.protobuf import json_format
from chromite.lib import osutils
+
+assert sys.version_info >= (3, 6), 'This module requires Python 3.6+'
+
+
FORMAT_BINARY = 1
FORMAT_JSON = 2
VALID_FORMATS = (FORMAT_BINARY, FORMAT_JSON)