One of the tasks that distributions have to deal with on a daily basis is ensuring that the code they package is as free of bug as humanly possible without having to run after upstream continuously. To solve this problem the usual solution is to use the upstream-provided releases, but also apply over those patches to fix issues and, most importantly, backports.
Backports are patches that upstream already accepted, and merged into the current development tree, applied over an older version (usually, the latest released version). Handling these together with external patches tends to get tricky, from one side you need to track down for the new release which have been merged already (just checking those that apply don’t do the trick, since you would probably find non-merged patches that don’t apply because source files changed between the two versions), from the other, they often apply with fuzz, which has been proven a liability with the latest GNU patch version.
Now, luckily, with time better tools have been created to handle patching: quilt is a very good one when you have to deal with generic packages, but even better than that is the git source control manager software. When you have an upstream repository in git, you can clone it, then create a new branch stemming from the latest release tag, and apply your patches, committing them right away exactly how they are. And thanks to the
cherry commands, handling backports (especially verifying whether they have been merged upstream) is piece of cake.
It even gets better when you use the
format-patch command to generate the patchset since they will be ordered, and described, right away; the only thing that it lacks is creating a patchset tarball right out of that, not that it’s overly difficult to do though (I should probably write a script and publish that). Add then tags, and the ability to reset branches and you can see how dealing with distribution patching via git gets much nicer than it was before the coming of git.
But even this has a relative usefulness when you keep the stuff just locally-available. So to solve this problem, and especially to remove myself as a single point of failure (given my background that’s quite something — and even more considering lately I had to spend most of my time on paid work projects, as life became suddenly, and sadly, quite complicated), I’ve decided to prepare and push out branches.
So you can see there is one repository for lxc (thanks to Adrian and Sven for the backports), and one for libvirt (thanks to Daniel that after daring me went on to merge the patches to the schema I made; two out of three are in, the last one is the only reason why nxml integration for libvirt files is not yet in).
Now, there is one other project I’d like to publish the patches of this way, and that project is iscsitarget; unfortunately upstream is still using Subversion so I’ve been using a git-svn bridge which is far from nice. On the other hand my reasoning to publish that is that I dropped iscistarget! — which means that if you’ve been relying on it, from next kernel release onward you’ll probably encounter build failures (I already fixed it to build with 2.6.32 beforehand since I was using release candidates for a while). Myself, I’ve moved to sys-block/tgt (thanks to Alexey) which does not require an external kernel module, but rather uses the SCSI target module that Linux already provides out of the box.