* make "git cat-file --batch" detect unlinked packfiles so we don't
have to restart processes (very long-term)
+
+* support searching based on `git-patch-id --stable` to improve
+ bidirectional mapping of commits <=> emails
+
+* linter to check validity of config file
+
+* linter option and WWW endpoint to graph relationships and flows
+ between inboxes, addresses maildirs, coderepos, etc...