Ensure deterministic toctree

Author: khanxmetu

sphinx/builders/__init__.py

@@ -613,6 +613,9 @@ def write(
                     docnames.add(tocdocname)
         docnames.add(self.config.root_doc)
 
+        # sort to ensure deterministic toctree generation
+        self.env.toctree_includes = dict(sorted(self.env.toctree_includes.items()))
+
         with progress_message(__('preparing documents')):
             self.prepare_writing(docnames)