Comment 1 for bug 800768

> Can then the packaging guide suggest to check debcheckout or something else like Vcs-Bzr to check which branch is actually the packaging branch?

That's the case for desktop packages, but not most of universe. There are packages with Vcs-Bzr pointing at alioth (I maintain a couple of those).

We discussed this in #ubuntu-devel the other night:
http://irclogs.ubuntu.com/2011/07/06/%23ubuntu-devel.html#t15:28

Either we need to:
1. mangle Vcs fields, so only Ubuntu-specific Vcs-Bzr fields remain,
2. use XS-Ubuntu-Vcs-Bzr, fallback to UDD,
3. use Vcs-Bzr when "ubuntu" is in the version, fallback to UDD,
4. look for "ubuntu" in Vcs-Bzr, fallback to UDD, or
5. combine 2 with 3 or 4

1. requires no tool changes.
1 and 2 but wouldn't be usable until every desktop package was updated.
2, 3, 4 and 5 require patching debcheckout / another tool (pull-lp-source could be taught to do this)

I don't think the packaging guide should be updated until a choice is taken here.