Fix python warnings: Use collections.abc instead collectionsjjardon/warnings_collections

Since python 3.3, collections has been moved to collections.abc module.
For backwards compatibility, they continue to be visible in this module through Python 3.7.
Subsequently, they will be removed entirely.

See https://docs.python.org/3/library/collections.html

1 files changed, 1 insertions, 1 deletions

diff --git a/buildstream/source.py b/buildstream/source.py
index ad7c57fb0..e42bad1a5 100644
--- a/buildstream/source.py
+++ b/buildstream/source.py
@@ -155,7 +155,7 @@ Class Reference
 """
 
 import os
-from collections import Mapping
+from collections.abc import Mapping
 from contextlib import contextmanager
 
 from . import Plugin, Consistency