diff --git a/src/buildstream_plugins/sources/cargo.py b/src/buildstream_plugins/sources/cargo.py
index fb143ac..268f624 100644
--- a/src/buildstream_plugins/sources/cargo.py
+++ b/src/buildstream_plugins/sources/cargo.py
@@ -375,7 +375,7 @@
 
     def set_ref(self, ref, node):
         node["ref"] = ref
-        self._recompute_crates(ref)
+        self._recompute_crates(node.get_sequence("ref"))
 
     def track(self, *, previous_sources_dir):
         new_ref = []
diff --git a/src/buildstream_plugins/sources/git.py b/src/buildstream_plugins/sources/git.py
index fb8a8a0..13c5fdf 100644
--- a/src/buildstream_plugins/sources/git.py
+++ b/src/buildstream_plugins/sources/git.py
@@ -827,14 +827,14 @@
             node["ref"] = self.mirror.ref = actual_ref
             self.mirror.tags = tags
             if tags:
-                node["tags"] = []
-                for tag, commit_ref, annotated in tags:
-                    data = {
+                node["tags"] = [
+                    {
                         "tag": tag,
                         "commit": commit_ref,
                         "annotated": annotated,
                     }
-                    node["tags"].append(data)
+                    for tag, commit_ref, annotated in tags
+                ]
             else:
                 if "tags" in node:
                     del node["tags"]