Revert "element: remove _is_required()/__required"

This reverts commit 750aa60ab3809167ff14c479068a328dc477de3e.

1 files changed, 8 insertions, 0 deletions

diff --git a/src/buildstream/element.py b/src/buildstream/element.py
index 8cb3d6e49..936ec9ae5 100644
--- a/src/buildstream/element.py
+++ b/src/buildstream/element.py
@@ -253,6 +253,7 @@ class Element(Plugin):
         self.__splits = None  # Resolved regex objects for computing split domains
         self.__whitelist_regex = None  # Resolved regex object to check if file is allowed to overlap
         self.__tainted = None  # Whether the artifact is tainted and should not be shared
+        self.__required = False  # Whether the artifact is required in the current session
         self.__artifact_files_required = False  # Whether artifact files are required in the local cache
         self.__build_result = None  # The result of assembling this Element (success, description, detail)
         self._build_log_path = None  # The path of the build log for this Element
@@ -1377,6 +1378,13 @@ class Element(Plugin):
         # Ensure deterministic owners of sources at build time
         vdirectory.set_deterministic_user()
 
+    # _is_required():
+    #
+    # Returns whether this element has been marked as required.
+    #
+    def _is_required(self):
+        return self.__required
+
     # _set_artifact_files_required():
     #
     # Mark artifact files for this element and its runtime dependencies as