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Ubuntu patches

As a few people have noticed, the Ubuntu patches repository is
currently producing some unusual results; in particular the patches
seem to include Debian changes as well as Ubuntu ones.

The patches are produced by a tool we oh-so-amusingly call NDA
(Nightly Difference Analysis), which like the MOM (Merge-o-Matic) tool
uses a 3-way diff to determine the differences between Debian and

To do a 3-way diff you need a common base version, which is usually
the Debian version on which the Ubuntu version is based.  You can then
generate a "Debian" patch which consists of the new changes in Debian
and an "Ubuntu" patch consisting of our changes.

When the desired base version is not available, we try increasingly
older base versions until we find the first one that is.  However this
means that Debian changes will show up in the Ubuntu patch.

We can pick on a source package to illustrate this, and I'll use
"netbase" as an example:


also contains the differences in the Debian "4.23" version.

A quick way of checking why this happens it to look in the
"ongoing-merge" directory for the REPORT file:


which contains the text:

    netbase -- Wed Jan 25 16:56:41 2006

    Previous Ubuntu Version: 4.23ubuntu4
    Current Debian Version:  4.24

    Base Debian Version:     4.22
            (Debian version on which I think Ubuntu is based)

to find out why it's got the base wrong, check the LOGS for that day
and look for the source package:



     * Processing netbase
       - unstable: 4.24
       - main: 4.23ubuntu4
       - testing: 4.24
       - stable: 4.21
       - oldstable: 4.07
       - morgue: 4.22

So the reason it didn't use 4.23 was simply that it isn't able to find
that source package anywhere.

(Note that making the above a bit less of a hunt, and putting it in
the REPORT file and linking the REPORT file into the patches tree is
high up on my TODO list.)

And the reason 4.23 isn't in the morgue is simple, Debian's morgue ran
out of disk space a while ago.  It hasn't been noticed by us because
we've already passed our Upstream Version Freeze for the upcoming
dapper release so haven't been using the merge output for a while.

First up it's obvious that we need a communication channel for Debian
developers to report problems and requests for the patches repository,
so I've registered NDA in Launchpad so you can use that to file
problems and requests:

File a request here:

And view open requests here:

And next it's obvious that for this to be useful, we need to fix the
problem.  If Debian is able to allocate more disk space to its morgue
then that obviously makes it go away.  Otherwise the solution is for
us to begin maintaining a source morgue ourselves for this purpose.

I hope that explains the situation well enough, if you have any
questions please ask me.  Note that I'm not subscribed to this mailing
list, so you'll need to break list policy and Cc me on replies if you
want my attention.



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