Revision 5 as of 2010-05-18 22:02:47

Clear message


  • provide a way to create new archives by branching a subset of ubuntu packages
  • make it easy to change these archives
  • manage differencies between archives and their (direct or no?) parents

Not sure if the distinction between full/slim archives is pertinent here? I mean, what type of archives would we be creating? AIUI, we need to create a full archive when the child archive includes toolchain changes that would cause binary incompatibility?

Release Note



This should cover the _why_: why is this change being proposed, what justifies it, where we see this justified.

User stories

  • Ted wants to package the latest version of the Foo project, which depends on the latest version of Bar and Baz, which in turn are not yet available in Ubuntu. Instead of packaging Bar and Baz, Joe can branch off of two existing PPAs that already have packages for the latest version of Bar and Baz. (This use case was invented to try and explain why we might want multiple parents, as discussed during the session)
  • A partner is developing a custom netbook UI but need to keep it private until it's finalized, so they create a slim archive off of the main Ubuntu archive and do any UI changes (or add new packages) on their new archive, which is only accessible by themselves. The slim archive is possible because it should be binary compatible with the main Ubuntu archive. Can/should the new archive be hosted on LP, like a private PPA?
  • YAP (Yet Another Partner) is working on optimizing their new (not-yet-released) chip, but for that they need a version of GCC newer than the one on the Ubuntu archive. They want to create a new (private) archive where they'll upload the new GCC version, but upgrading to that new version of GCC is known to break binary compatibility, so it must be possible for them to easily rebuild all packages using the new GCC.

Is related to this in any way?


  • archives can be refered to by their URLs. (I think this is how we're going to tell the tools the archives they'll operate on.


You can have subsections that better describe specific parts of the issue.


This section should describe a plan of action (the "how") to implement the changes discussed. Could include subsections like:

UI Changes

Should cover changes required to the UI, or specific UI that is required to implement this

Code Changes

Code changes should include an overview of what needs to change, and in some cases even the specific details.



  • data migration, if any
  • redirects from old URLs to new ones, if any
  • how users will be pointed to the new way of doing things, if necessary.

Test/Demo Plan

It's important that we are able to test new features, and demonstrate them to users. Use this section to describe a short plan that anybody can follow that demonstrates the feature is working. This can then be used during testing, and to show off after release. Please add an entry to for tracking test coverage.

This need not be added or completed until the specification is nearing beta.

Unresolved issues

This should highlight any issues that should be addressed in further specifications, and not problems with the specification itself; since any specification with problems cannot be approved.

BoF agenda and discussion


  • Goal: branch subset of ubuntu packages and manage changes
    • experiments - short/adhoc / long running
    • multiple parents: e.g. integrate goodies from multiple PPAs
    • hierarchy: common archive -> project archive -> project variant archive etc.

      • automatic superseding and merging


  • Release/Freezes/ACLs
    • have automatic merged release branch owned by releaes team during development
      • period that gets set to manual mode during freezes.
    • at release another branch is auto created that is not changeable??

Getting Started

  • getting started: command line tool to branch some archive; by default it starts
    • by copying the binaries;
  • managing changes: webtool that visualizes relationship to parent archive:
    • changes in downstream archive
    • changes in upstream archive (merge o matic'ish)
  • some changes like gcc would require move a binary copy archive to a source/rebuild
    • everything mode? is that true? gcc might just have changed for a bug fix/crash etc.
    • tracking build dependencies may be relevant here
  • a way of enforcing version number rules in a particular archive would be good