[Biopython-dev] Subversion Repository

[Chris Lasher]

On 3/22/07, Michiel de Hoon <mdehoon at c2b2.columbia.edu> wrote:
> Maybe this is a silly question but will there be some downtime during
> the cvs->svn conversion? And can we still make commits to cvs or is it
> better to wait until the conversion is complete?

Ah, very good question, Michiel. Yes, there will be downtime for the
CVS repository. As Marc mentioned, it would probably be one evening.

Also, to clarify, once the conversion is complete, CVS commits won't
be permitted. If we decide to maintain CVS at all, it will only be
possible to check out and update from CVS. (In other words CVS becomes
"read-only".) All commits will go through Subversion, and there are
two main reasons for this:

 1) There is no easy means by which we can keep the two in sync going
both ways. The Subversion to CVS syncronization is quite a bit of
hackery on its own.

2) Subversion effectively deprecates CVS. Taken straight from Subversion's site:

> Subversion is meant to be a better CVS, so it has most
> of CVS's features. Generally, Subversion's interface to
> a particular feature is similar to CVS's, except where
> there's a compelling reason to do otherwise.

So, aside from the natural human propensity for fear of change, why
one would want to continue to work via CVS escapes me.

I am not keen on supporting CVS with updates after the transition, but
if users must have access to it, I will put in the work it takes to
make that happen. In any event, we will strongly encourage Biopython
users to make the transition to Subversion.

I need to draft a migration strategy which includes the following:
 * documentation for developers on switching over to Subversion, in
general (available via the Subversion Book), and in the specific
context of Biopython, particularly
 * documentation for users on how to checkout and update Biopython via
Subversion
 * the nitty gritty technical details of how we will proceed with the
conversion--useful for the other Open-Bio projects which will want to
follow in Biopython's wake

I will begin writing this documentation on the Biopython wiki this
weekend. I would like to set a target date for the CVS to Subversion
transition for May 20th, which gives about two months' worth of
anticipation for developers (and users, once I get an email out to
that list), and plenty of time prior to BOSC 2007 for the growing
pains caused by the transition to be worked out.

How does this sound--any red flags or glaring omissions?

Chris