tr-summary: keep a weakref to the unfiltered repository Repoview can have a different life cycle, causing issue in some corner cases. The particular instance that revealed this comes from localpeer. The localpeer hold a reference to the unfiltered repository, but calling 'local()' will create an on-demand 'visible' repoview. That repoview can be garbaged collected any time. Here is a simplified step by step reproduction:: 1) tr = peer.local().transaction('foo') 2) tr.close() After (1), the repoview object is garbage collected, so weakref used in (2) point to nothing. Thanks to Sean Farley for helping raising and debugging this issue.