--- /dev/null
+There is no obvious means of using
+".be/version"/"libbe.bugdir.TREE_VERSION_STRING". In the past I've
+worked around this by keeping all the disk-reading backwards
+compatible (e.g. homemade mapfile -> YAML, the "From" hack in
+libbe.comment.Comment.load_settings, possibly others). However, this
+is not the road to easily maintainable code.
+
+Most projects only need to maintain backwards compatibility with the
+last few versions of their disk cache, to allow users an easy upgrade
+path. The difficulties come with "be diff", which must be able to
+read _every_ disk-image of the bugdir ever committed into something
+comparible with the current cutting edge. This makes sweeping changes
+very difficult. VCSs themselves avoid this by never showing their
+disk-cache to another program, but we've shown ours to the VCS, and
+it's difficult (or impossible, depending on the VCS) to change history
+to match the current format.
--- /dev/null
+creator: W. Trevor King <wking@drexel.edu>
+
+
+reporter: W. Trevor King <wking@drexel.edu>
+
+
+severity: minor
+
+
+status: open
+
+
+summary: Upgrade path for on-disk representation
+
+
+time: Sun, 16 Aug 2009 19:05:59 +0000
+