Question

I’m tracking a project that has recently moved from svn to git. I’ve got the most recent svn code and want to start using the code from git. Is there a way to do this that doesn’t involve re-downloading quite a large codebase over a slow connection? Essentially, I want to be able to say “start from here (old svn code) and just get the changes from git”.

Answer 1

SVN & Git may seem similar because they’re both SCM tools, but under the hood, they’re implemented very different, i.e. Git is way better.

Just start from fresh and git clone it. Even for large projects like the Linux Kernel, Git is very fast at cloning.

You could also use the --depth option to speed things up:

–depth <depth>

Create a shallow clone with a history truncated to the
specified number of revisions. A shallow repository has a
number of limitations (you cannot clone or fetch from
it, nor push from nor into it), but is adequate if you
are only interested in the recent history of a large project
with a long history, and would want to send in fixes
as patches.

Source: http://git-scm.com/docs/git-clone

Here’s an example that checks out the most recent version of the repository:

git clone git://source.winehq.org/git/wine.git ~/wine-git --depth 1

Source: http://mortalpowers.com/news/speed-up-git-clone-with-shallow-clones

You can later use the --depth option with git pull:

–depth=<depth>

Deepen the history of a shallow repository created by
git clone with –depth=<depth> option by the specified number of commits.

Source: http://kernel.org/pub/software/scm/git/docs/git-pull.html

Perhaps, if you put a large enough number (or maybe -1?) for depth so as to pull in the entire history of the repository, then you’ll have all the functionality of a normal repository, e.g., the ability to clone or fetch from it, or push from or into it.

If not, you can just clone it normally in a separate place (perhaps when you have a faster connection) and use git format-patch and git apply to move your commits from the shallow repository into the new one.

Matt