Question

How can I clone a git repo from my laptop (at home) to a server (at university) while getting most of the repo from a third (svn) repo at another uni that is the main codebase. I’d like to minimise the amount of home<->uni traffic by maximising uniOne<->uniTwo traffic.

this is what I have now on Laptop:

--o--o--o---o---o---o git-svn trunk  
         `--o--o-o--o git mybranch  

this is what I would like to get on uniOne:

--o--o--o---o---o---o git-svn trunk <-- from uniTwo  
         `--o--o-o--o git mybranch  <-- from Laptop

After cloning the repo should be able to pull branches from Laptop.

I have tried: on uniOne: git-svn clone uniTwo, git remote add Laptop, but then git fetch wants to get the whole thing from Laptop. I thought maybe using git clone –depth x Laptop and then graft them together might work but it still requires all of the source files to be transfered Laptop->uniOne, not just the changes. I could try to export all patches from Laptop and apply them on top of a fresh svn checkout then get it to track the branch on my Laptop (if that is possible) but it would be easier to wait until I am next at uni and then just clone normally.

Answer 1

Let’s define your repositories:

• git-svn <– this is the Subversion repository at University
• uni/master <– this is a Git repository at your University. This is jus a “fetching repository” that gets the latest history from the Subversion repo.
• laptop/master <– This is the Git repository on your laptop. This is where you work.

I would suggest the following setup:

Create uni/master by doing git svn clone of git-svn.
Automatically or regularly update uni/master with the latest changes from git-svn by running git svn rebase (trigger with a commit hook, cron-job, or manually every time you’re at Uni).

Create laptop/master by cloning uni/master. Here you can commit locally as often as you want. When you are at University, get the latest changes from uni/master by running git pull --rebase (you always have to do –rebase to keep history linear, because SVN won’t understand git-branches).

When you want to push changes from your laptop back to git-svn, you have to configure the git-svn remote on your laptop/master first:

git svn init https://url.to.uni-svn-repo

Now you can push your latest changes back to uni-svn with git svn dcommit. Note that you might have to update the reference to the latest commit in uni/master first. first:

git update-ref refs/remotes/git-svn refs/remotes/uni/master

DO NOT attempt to push from your laptop/master to uni/master. This will only bring chaos as the rebasing/rewriting history will just confuse Git when it tries to sync with git-svn again.

See also http://www.tfnico.com/presentations/git-and-subversion where I’ve started collecting up a bunch of tips for working with Git and SVN together.