Re: [eigen] git

[Keir Mierle <mierle@xxxxxxxxx>]

On Tue, Apr 28, 2009 at 5:53 AM, Benoit Jacob <jacob.benoit.1@xxxxxxxxx> wrote:
> Hi,
>
> We're considering moving to Git (or another DVCS).

Excellent! DVCS is the future of open source version control. The
argument is less clear in the corporate environment, but for open
source it is ideal because it lowers barriers to entry.

> The motivation is that lately there's been an increasing number of
> people doing experiments around Eigen, and so far we haven't found a
> way of making Eigen's SVN really friendly to that. There are 2 types
> of problems:
> a) one only asks for a KDE SVN account if one knows one'll keep
> contributing in the future. But many people just want to be able to do
> experiments with Eigen, code a potential new module, without making
> that kind of commitment right away.
> b) SVN is not as friendly as a DCVS for doing experiments and letting
> other people use the code without commiting to the central repository.
>
> We created the unsupported/ directory where we can add stuff without
> being worried about maintainance, but that didn't solve the above
> issues.
>
> I don't know much about Git or DVCS's in general but my impression is
> that it makes it easier to create your own branch of Eigen and then
> let other people use it. I also believe that git is far more clever
> than SVN at merging different branches. I would be interested in links
> explaining how this is the case... or proving me wrong.
>
> All this means moving out of the KDE tree (even if KDE moves to git in
> the future that wouldn't solve a)).
> But at the moment we have KDE trunk that relies on Eigen trunk. So in
> order to keep things convenient for KDE, we could, in the short term,
> keep a copy of eigen in kdesupport, where it is now, and update it
> from time to time by re-syncing with the git repo (any pointer
> appreciated as to best practice to do that).
> As soon as Eigen 2.1 is released and distros have packages, we'll tell
> people to use that. As, in the future, KDE will track eigen
> development less closely, we'll be able to remove the copy in
> kdesupport.
>
> I absolutely want to preserve 100% of the SVN commit history across
> this change. I was told this is possible and a friend offered to do
> the move for us.
>
> Questions:
> a) Git or Mercurial or another DVCS? Here like elsewhere, I expect git
> to be the most popular, but I don't have any opinions of my own as I'm
> very ignorant in these matters. From IRC and mail I received several
> "votes" for git and 1 for mercurial.

Both are excellent. Hg is a bit easier to use.

> b) Where to look for hosting? I heard that github is nice and offers
> useful features. The alternative would be tuxfamily which offers plain
> git repos, but certainly not with the same fancy features.

One plus for mercurial is that code.google.com will support it soon.
code.google.com has built-in code review support; just one less item
for the eigen devs to configure themselves.

Keir

> c) Any good git tutorial you'd especially recommend? especially
> regarding dealing with different branches ?
>
> Cheers,
> Benoit
>
>
>