_compat.py: Add module to handle version compatibility in pythonbschubert/fix-resource-deletion

This adds a module that allows us to patch some utilities when they
are version conflicts.

Let's keep them all in a specific place, which will make things easier
when removing support for previous versions whenever possible.

2 files changed, 33 insertions, 0 deletions

diff --git a/src/buildstream/__init__.py b/src/buildstream/__init__.py
index c78fcbbf6..40746d735 100644
--- a/src/buildstream/__init__.py
+++ b/src/buildstream/__init__.py
@@ -28,6 +28,7 @@ if "_BST_COMPLETION" not in os.environ:
     __version__ = get_versions()["version"]
     del get_versions
 
+    from . import _compat
     from .utils import UtilError, ProgramNotFoundError
     from .sandbox import Sandbox, SandboxFlags, SandboxCommandError
     from .types import Scope, Consistency, CoreWarnings
diff --git a/src/buildstream/_compat.py b/src/buildstream/_compat.py
new file mode 100644
index 000000000..1c8c99d73
--- /dev/null
+++ b/src/buildstream/_compat.py
@@ -0,0 +1,32 @@
+#
+#  Copyright (C) 2019 Bloomberg Finance LP
+#
+#  This program is free software; you can redistribute it and/or
+#  modify it under the terms of the GNU Lesser General Public
+#  License as published by the Free Software Foundation; either
+#  version 2 of the License, or (at your option) any later version.
+#
+#  This library is distributed in the hope that it will be useful,
+#  but WITHOUT ANY WARRANTY; without even the implied warranty of
+#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	 See the GNU
+#  Lesser General Public License for more details.
+#
+#  You should have received a copy of the GNU Lesser General Public
+#  License along with this library. If not, see <http://www.gnu.org/licenses/>.
+#
+
+# This module contains some patches to make it easier to handle different
+# python versions. Patches can be removed once we decide a specific version
+# does not need to be supported anymore.
+
+import sys
+
+# Python < 3.7
+if sys.version_info[:2] < (3, 7):
+    # multiprocessing.Process got a 'close' method on python3.7
+    # A no-op is fine for previous versions
+    import multiprocessing
+    def _close(self):
+        pass
+
+    multiprocessing.Process.close = _close