[Numpy-discussion] Moving away from svn ?

[David Cournapeau]

Gael Varoquaux wrote:
> On Fri, Jan 04, 2008 at 08:54:13PM +0900, David Cournapeau wrote:
>> I certainly agree that changing the VCS is a big change, and requires a 
>> lot of thinking, though. I am not suggesting to change for the next week.
>
> In the mean time, do you want to tell us more about how you use bzr with
> svn. This seems like a good transitory option.
Once you installed bzr-svn, you can import the whole scikits trunk using 
the svn-import command. This will create a shared repository (that is no 
working tree is actually put in scikits.bzr: this means that having the 
whole repository is quite cheap storage-wise; as an example, the whole 
scipy history takes around 68 Mb, that is less than a svn checkout with 
the working tree). Once you have the shared repository, you do not care 
anymore that it is imported from svn. It is exactly the same worklow as 
a native bzr shared repository.

The problems:
     - importing is really slow, because you need to get the history per 
revision; this is a network-bound operation (for local svn mirrors, on a 
macbook, I can import around 15 revisions/second for matplotlib, at 
which point it becomes CPU bound). That's why I asked about svn server 
informations, to be able to use svnsync (which makes a local mirror of a 
svn repository) for thorough experiments on my own.
    - because of the above, it would be really bad if many people start 
to import directly, because of the burden on the svn server.
    - bzr-svn uses a different format than usual bzr. UI wise, it does 
not change anything, but this means it is less performant than the 
format used since bzr 0.92 (it is an over-simplification, because you 
can have a better format).
    - It does not work right now with numpy because I made a mistake + a 
bzr-svn bug, which should be easily solved, though. It works with scipy 
and scikits.

David