Recipes vs. Looms

[James Westby]

On Tue Dec 15 00:32:36 +0000 2009 Michael Hudson wrote:
> Although it would be nice to finally get our heads down and start
> hacking, I agree it would be a good idea to decide if we're going in the
> right direction.
> 
> That said, I think what you're talking about in this mail is more
> focused on the "helping existing ubuntu developers" side of the coin
> than the "daily builds" side?

Yes. Do you have some comment from the other side? Do they significantly
change the outcome?

> Most debian patch systems apply the patches in a predefined order though
> don't they?  It doesn't seem too ridiculous to me to keep that in the loom.

Agreed.

> > There are alternative models proposed, including
> > a full DAG as implemented by TopGit. My fear is that they are
> > too complicated for people to easily grasp, and that they are
> > not the best way to solve the problems they aim to.
> > 
> > Looms also allow for versioning at the loom level, as well
> > as at the revision level. This means that it is possible
> > to merge a loom as a whole,
> 
> In principle only, right?  I don't think that this code exists yet.

I think there is some code, but it's not production-ready yet.

> > including operations that
> > add and delete threads. This is crucial to building a
> > packaging system on top of them.
> 
> It has to be said that I have never confidently been able to predict
> what doing "bzr push" in a loom would do.  This falls into the "polish
> required" category I guess.

You mean whether it pushes out that thread to a standalone branch or
pushes the whole loom? I would agree that could be tricky.

I believe the current answer depends on what is already at the target.

> > Looms also have a nice two-way mapping to the new v3 source
> > format, so we could both present Debian's packages as looms,
> > and present Debian with v3 source packages.
> 
> What about other debian formats?  Would you like to have
> lp:ubuntu/firefox be a loom?  I think it more or less has to be for this
> approach to be useful.

Yes, I was assuming that the Debian/Ubuntu branches would be looms.

(As an aside, one downside of going this route is that I have no idea yet
 how to draw a picture of two divergent looms :-)

Thanks,

James