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Entry  13 Feb 2013, Konstantin Olchanski, Info, Review of github and bitbucket 
    Reply  14 Feb 2013, Stefan Ritt, Info, Review of github and bitbucket 
       Reply  01 Apr 2013, Randolf Pohl, Info, Review of github and bitbucket 
          Reply  02 Apr 2013, Konstantin Olchanski, Info, Review of github and bitbucket 
             Reply  02 Apr 2013, Randolf Pohl, Info, Review of github and bitbucket 
          Reply  03 Apr 2013, Stefan Ritt, Info, Review of github and bitbucket 
             Reply  03 Apr 2013, Randolf Pohl, Info, Review of github and bitbucket 
Message ID: 869     Entry time: 02 Apr 2013     In reply to: 868
Author: Randolf Pohl 
Topic: Info 
Subject: Review of github and bitbucket 
Hi Konstantin,

> > * No central repo. Have all the history with you on the train.
> > * Branching and merging, with stable branches and feature branches.
> >   Happy hacking while my students do analysis on a stable version.
> >   Or multiple development branches for several features.
> 
> This is the part that worries me the most. Without a "central" "authoritative" repository,
> in just a few quick days, everybody will have their own incompatible version of midas.

No! This is probably one of the biggest misunderstandings of the git workflow.

You can of course _define_ one central repo: This is the one that you and Stefan decide to be "the source" (as
Linus does for the kernel). It's like the central svn repo: Only Stefan and you can push to it, and everybody
else will pull from it. Why should I pull MIDAS from some obscure source, when your "public" repo is available.

Look at the Linux Kernel: Linus' version is authoritative, even though everybody and his best friend has his
own kernel repo.

So, the main workflow does not change a lot: You collect patches, commit them, and "push" them to the central
repo. All users "pull" from this central repo. This is very much what svn offers.

> 
> I guess I am okey with your private midas diverging from mainstream, but when *I* end up
> with 10 different incompatible versions just in *my* repository, can that be good?

See above: _You_ define what the central repo is.

But: I _bet_ you will very soon have 10 versions in your personal repo, because _you choose_ to do so. It's
just SO much easier. The non-linear history with many branches is a _feature_. I can't live without it any more:


Looking at my MIDAS analyzer:

I have a "public" repo in /pub/git/lamb.git. This is where I publish my analyzer versions. All my collaborators
pull from this.

Then I have my personal repo in ~/src/lamb. 
This is where I develop. When I think something is ready for the public, I merge this branch into the public repo. 

Whenever I start to work on a new feature, I create a branch in my _local_ repo (~/src/lamb).  I can fiddle and
play, not affecting anybody else, because it never sees the public repo.
OK, collaborator A finds a bug. I switch to my local copy of the public version, fix the bug, and push the fix
to the publix repo. Then I go back to my (local) feature branch, merge the bug fix, and continue hacking.
Only when the feature is ready, I push it to the public repo.

Things get moe interesting as you work on several features simultaneously. You have e.g. 3 topic branches:
(a) is nearly ready, and you want a bunch of people to test it.
    push branch "feature (a)" to the public repo and tell the people which branch to pull.
(b) is WIP, you hack on it without affecting (a).
(c) is bug fixes which may or may not affect (a) or (b).
And so on.

You will soon discover the beauty of several parallel branches.

Plus, git merges are SO simple that you never think about "how to merge"

> 
> >   And merging really works, including fixing up merge conflicts.
> 
> But somebody still has to do it. With a central repository, the problem takes care of
> itself - each developer has to do their own merging - with svn, you cannot commit
> to the head without merging the head into your code first. But with git, I can just throw
> my changes int some branch out there hoping that somebody else would do the merging.
> But guess what, there aint anybody home but us chickens. We do not have a mad finn here
> to enforce discipline and keep us in shape...

See above: You will have the exact same workflow in git, if you like.




> As an example, look at the HADOOP/HDFS code development, they have at least 3 "mainstream"
> branches going, neither has all the features combined together and each branch has bugs with
> the fixes in a different branch. What a way to run a railroad.

I haven't look at this. All I can say: Branches are one of the best features.

> 
> > * "git bisect" for finding which commit introduced a (reproducible) bug.
> > * "gitk --all"
> >
> > Go for git. :-)
> 
> Absolutely. For me, as soon as I can wrap my head around this business of "who does all the merging".

Easy: YOU do it.

Keep going as in svn: Collect patches, and send them out.

And then, try "git checkout -b my_first_branch", hack, hack, hack,
"git merge master".

Best,

Randolf


> 
> K.O.
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