- Create a Herald rule that triggers for "commit is on autoclose branch".
- Create a commit on a non-autoclose branch that has the head of an autoclose branch as its parent, and push it. The herald transcript should show the commit as not matching the rule (since it isn't on an autoclose branch).
- Update (fast-forward) the head of the autoclose branch to point at the new commit.
- Push the autoclose branch.
Herald doesn't trigger for this commit, because no commit was created (only a branch was updated).
I'm working around this issue for now by tracking only autoclose branches.