On Thu, Oct 18, 2012 at 08:16:50PM -0700, Russ Allbery wrote: > Steve Langasek <vorlon@debian.org> writes: > > The last time I complained about non-pristine-tar git package repos on > > IRC, I was told that pristine-tar doesn't scale. So apparently in git > > usage, folks haven't worked out that the unpacked upstream source should > > be tracked as a branch instead of trying to track a pristine-tar delta > > against the upstream git branch directly. > What did you mean by that last sentence? I was unable to parse it. In > particular, I think I don't understand the difference between "tracked as > a branch" and "track a pristine-tar delta against the upstream git > branch," which both sound like they mean the same thing. The UDD branch model used in Launchpad has three branches (not counting the pristine-tar objects): - the upstream branch (as it exists upstream) - a synthesized branch which merges from the upstream branch and tracks the contents of the upstream tarball releases /as contents/ - the packaging branch AIUI, most users of pristine-tar in git don't have the second of these branches, which means the pristine-tar binary delta is done against the upstream branch - so each pristine-tar blob contains all the information about autogenerated files in the tarball, in a format that doesn't in turn compress well in the git repository. And if your packaging branch actually tracks the full source package contents, then it would have to track the autogenerated files, so you might actually be storing these files twice. In UDD, the delta to the autogenerated files from one upstream release to the next is stored like any other branch delta, and the pristine-tar blob only has to account for the tarball/gzip metadata itself. I believe this was done by design precisely in order to address the pristine-tar scalability problem; in any case, I don't hear complaints about pristine-tar being unusable for Ubuntu packages for the reasons people seem to be shunning it for Debian packages in git. -- Steve Langasek Give me a lever long enough and a Free OS Debian Developer to set it on, and I can move the world. Ubuntu Developer http://www.debian.org/ slangasek@ubuntu.com vorlon@debian.org
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