diff --git a/buildstream/utils.py b/buildstream/utils.py
index 968d87f7bf83177476249f4c8f9ba927004103dc..8e105230a6701139d2acc16b55614069ddb31fc3 100644
--- a/buildstream/utils.py
+++ b/buildstream/utils.py
@@ -1236,3 +1236,17 @@ def _deduplicate(iterable, key=None):
 def _get_link_mtime(path):
     path_stat = os.lstat(path)
     return path_stat.st_mtime
+
+
+# Returns the first directory to contain filename, or an empty string if
+# none found
+#
+def _search_upward_for_file(directory, filename):
+    directory = os.path.abspath(directory)
+    while not os.path.isfile(os.path.join(directory, filename)):
+        parent_dir = os.path.dirname(directory)
+        if directory == parent_dir:
+            return ""
+        directory = parent_dir
+
+    return directory