bzr to have shallow partial clones (stacked branches) soon

[Peter Arrenbrecht]

On Sat, May 31, 2008 at 6:54 AM, Giorgos Keramidas
<keramida at ceid.upatras.gr> wrote:
> On Fri, 30 May 2008 18:15:25 +0200,
> Peter Arrenbrecht <peter.arrenbrecht at gmail.com> wrote:
>> http://jam-bazaar.blogspot.com/2008/05/this-week-in-bazaar_29.html
>>
>> Maybe we can borrow some of the terminology once Hg gets there too.
>>
>> How's interest in such a feature here on the list?
>
> It sounds like a nice feature.  The full history of the FreeBSD source
> includes a couple of hundred thousands revisions.  Cloning the entire
> src/ repository with 1-2 Gb of history just to hack on the src/bin/ls
> directory is bound to be a lot of pain.
>
> With something similar to the 'stacked branches', it would be wonderful
> to be able to keep a *single* clone of the FreeBSD tree, i.e. at a
> central place of a laptop disk like `/repos/bsd/src' and then create
> `very cheap' clones for personal work at:
>
>    WORKSPACE            DISK-SIZE DESCRIPTION
>    ~/ws/ls-stat-fixes       80 KB (tiny userland tool)
>    ~/ws/kernel-locking     128 MB (instead of ~= 1 GB)
>
> If each `cheap' clone was a `lightweight branch' which only maintained a
> reference to the parent tree, and required 2-3 KB of disk space, this
> would make things a *lot* nicer.
>
> It's almost 50% of the solution to the reasons why dVCS adoption is
> difficult to `sell' for projects with such a big history:
>
>    * Very large .hg/ history for all clones (which makes multiple
>      clones a bit expensive in disk space where hardlinks are not
>      always an option).
>
>    * Lack of `partial checkouts' (which makes it a bit hard to work
>      with only `src/sys/dev/sound/pci', if 500 MB of source have to be
>      checked out to get a full `tip' checkout).
>
> I'd be definitely interested in something that supported either of these
> two or both :)

Actually there is a GSoC project under way to address at least the
second item on your list. If possible also the first. Had slipped my
mind when I posted the blog link.
-parren