[AstroPy] proposal for astropy version control software and respository

[Perry Greenfield]

On Jul 15, 2011, at 5:50 PM, Mark Sienkiewicz wrote:

> Perry Greenfield wrote:
>> Given discussions at scipy (consisting primarily of a good number of
>> people from STScI, CFA/Chandra, and Gemini) it seemed clear to most  
>> of
>> us there that the most straightforward choice for the astropy version
>> control software and repository was git and github.
>
>
> I was corresponding off-list (IIRC) about using git, but I'll repeat  
> my
> major points here for everyone:
>
> - If the project will use git, the git advocates have a responsibility
> to present a clearly-defined work flow for each role in the project.
>
At some point this is necessary.  I don't think it is necessary before  
deciding to use it. More on that later.

> Motivation:  git implements several mutually-incompatible work flows.
> If you don't say which one you are using, you can get really screwed
> up.  Also, what you do with git and why anybody would want to do that
> are not obvious to those of us who are not already converts.  I am  
> your
> audience: one of those subversion users who "look at git's features  
> with
> confusion or disinterest".
>
Because we (STScI) don't need most of those features for our internal  
work (and I think from what I understand, we generally don't) doesn't  
mean they are useless for astropy though.

> b.t.w. I hear that ipython has a work flow document that we can  
> adapt from.
>
>
> - DVCS advocates in general seem to care deeply about the DVCSness of
> the system.  I don't need anything from git that I can't get from
> subversion, but the git advocates are so insistent that I might as  
> well
> just give up and say "ok, use git".  Basically, they care, I don't,  
> and
> I can probably make their favorite system work.  Assuming they explain
> the work flow.
>
> But it would sure suck to lose the revision numbers that subversion  
> has
> (but git does not) and not get something pretty intensely useful in
> return.  I hope you git guys know what that is.

I'm not sure what you mean here. Revision numbers in what sense? Git  
does track versions by numbers (if very large ones...). Do you mean  
numbers that have some sequential properties or something like that?

But let's step back a bit here. I'd venture to say that a lot more git  
users have used svn than the other way around. They are probably going  
to be more knowledgeable about the comparative advantages of the two  
systems than most svn users.

Secondly, yes, there are lots of different possible workflows that one  
could use with git, and one could, in principle, make a mess of  
things. But the fact is that a lot of projects are using git very  
nicely. If it often caused an unholy mess, I don't think they are such  
religious zealots that they would overlook that aspect. They generally  
are making it work one way or another.

Lastly, astropy, at least in principle could take advantage of the  
DVCS features much more than we do internally.

So no, I don't think all the details need to be spelled out ahead of  
time before a poll is taken. Those details can be worked out if there  
appears to a sizable majority willing to go that way. Given that most  
of the other python science projects are using it is a good reason not  
to buck the trend.

Perry