Index: trac/versioncontrol/web_ui/changeset.py
===================================================================
--- trac/versioncontrol/web_ui/changeset.py	(revision 6489)
+++ trac/versioncontrol/web_ui/changeset.py	(working copy)
@@ -797,6 +797,9 @@
     def render_timeline_event(self, context, field, event):
         changesets, message, show_location, show_files = event[3]
         rev_b, rev_a = changesets[0].rev, changesets[-1].rev
+
+        #### debug
+        raise ValueError("Bam!")
         
         if field == 'url':
             if rev_a == rev_b: