element.py: Add BST_RUN_COMMANDS flag

This flag indicates whether the plugin may run commands using
`Sandbox.run()` and defaults to `True`. This will allow faster staging
for plugins that do not need to run any commands in the sandbox.

1 files changed, 6 insertions, 0 deletions

diff --git a/buildstream/element.py b/buildstream/element.py
index 7331a6230..54e30cbbf 100644
--- a/buildstream/element.py
+++ b/buildstream/element.py
@@ -178,6 +178,12 @@ class Element(Plugin):
     *Since: 1.4*
     """
 
+    BST_RUN_COMMANDS = True
+    """Whether the element may run commands using Sandbox.run.
+
+    *Since: 1.4*
+    """
+
     def __init__(self, context, project, meta, plugin_conf):
 
         self.__cache_key_dict = None            # Dict for cache key calculation