Better Morgue For Ubuntu

Summary

This proposal makes the case and outlines the design of a better package morgue (area where old versions of packages are kept), more suited to Ubuntu work than the current solutions.

Rationale

In many areas of Ubuntu (for example MOTU), an important part of the work being done is about divergence management. Keeping old versions of packages around makes it much easier to do such work, as shown by this example : imagine that the current Ubuntu version of a package is 1.0-1ubuntu1. You have to work on the merge of Debian's 1.0-2. Ideally, you need Debian's 1.0-1, so you get :

Merging is easy : you just have to compare the two diffs.

Now, if you are unlucky, Debian's 1.0-1 is no longer available. So, maybe, you get 0.9-1. But the two diffs are much bigger, difficult to compare. And you can't know exactly what are the changes made to the Ubuntu version (the changelogs aren't always verbose enough).

So we need the latest common version as a base for our diffs.

How does MoM currently handle this ?

MoM uses several origins for the source packages :

So, since last november, MoM has only used Debian's sources.

Design ideas

The main problem with the two morgues is that they aim at keeping all packages. For Ubuntu work, this is not necessary : we only need to keep the versions which are actually useful for us. While snapshots.d.n uses about 2 To, 50 Go should be enough for us, keeping the useful packages for two Ubuntu releases.

The morgue could be implemented as four parts :

It would probably require 2 or 3 days of work to make it work perfectly.

Outstanding issues


CategorySpec

BetterMorgueForUbuntu (last edited 2008-08-06 16:24:35 by localhost)