Roundup is supremely flexible.  

What would make it even more so is if we could store our issues (and
everything else) as files and directories which could then be version
controlled. To support distributed version control, it would help if
roundup objects could have non-sequential names, ie. derived from some
sort of hash.  A good example of this in action is the bugs-everywhere
tracker:
 - http://bugseverywhere.org/be/show/HomePage

What would be awesome if there could be something with the generality of
roundup but the DVCS-friendliness of bugs-everywhere, because it is
extremely reassuring to be able to consult and update one's bug tracker
offline.

At first, in msg3930 I thought this was what issue2550547 was all about,
but after reading
http://www.scribd.com/doc/16508428/Google-Summer-of-Code-2009-Roundup-Improvements
I see that this was solving a slightly different problem (making roundup
notice changes reported via VCS).