element.py: Consider execution environment in cache key

Do this by default for every element, later we will have
to handle it differently when supporting projects which
build on specific arches with virtualization or networked workers.

1 files changed, 10 insertions, 0 deletions

diff --git a/buildstream/element.py b/buildstream/element.py
index afcfcee95..608c6e8c0 100644
--- a/buildstream/element.py
+++ b/buildstream/element.py
@@ -910,12 +910,22 @@ class Element(Plugin):
 
             context = self._get_context()
             project = self._get_project()
+            operating_system, _, _, _, machine_arch = os.uname()
+
             self.__cache_key_dict = {
                 'artifact-version': "{}.{}".format(BST_CORE_ARTIFACT_VERSION,
                                                    self.BST_ARTIFACT_VERSION),
                 'context': context._get_cache_key(),
                 'project': project._get_cache_key(),
                 'element': self.get_unique_key(),
+
+                # The execution environment may later be delegated
+                # to sandboxes which support virtualization
+                #
+                'execution-environment': {
+                    'os': operating_system,
+                    'arch': machine_arch
+                },
                 'environment': cache_env,
                 'sources': [s._get_unique_key() for s in self.__sources],
                 'public': self.__public,