pin the declared closure once per rebuild and seed the marker from the running closure

swarm-controller/src/meta_flake.rs

@@ -850,7 +850,7 @@ mod tests {
         );
         assert!(
             reads.contains(&("internal/meta".to_owned(), None)),
-            "the meta repo is read on its default branch, as hive-c0re reads it"
+            "the meta repo is read on its default branch"
         );
     }