Comment 22 for bug 163694

Point (2) from mpt's summary only seems really useful once LP has a notion of what those versions actually mean. Sure, it would be nice to record the data rather than systematically losing it, but I think adding support for that needs to be on somebody's plan somewhere. A date-based cut-off is distinctly suboptimal for Ubuntu and probably for many other projects as well, because the date you want depends on the version that the user is running. Indeed, if Launchpad had a way to record versions in which a bug was found as well, it would be possible to be much more accurate still about which bugs we show users: there's no point showing Hardy users a list of bugs that existed only for a couple of days in Lucid, at least not at the top of their list.

This general facility is called "version tracking" in Debian, and has been in debbugs since 2005 (http://lists.debian.org/debian-devel-announce/2005/07/msg00010.html). It was in the original design for Launchpad Bugs (under the name "infestations", which I never particularly liked ...), but was cut due, as I understand it, to time constraints. At Launchpad's current scale, I think it would be worth revisiting this decision; it is very useful when tracking multiple release series of software.