Git

Instead of using Subversion for developing MediaWiki you can use Git's gateway.

Why use Git instead of Subversion?
The major reason to use git-svn is because you like git more than Subversion. You'll wind up with a git repository that you can use like any other git repository. "git svn rebase" will fetch all commits and rebase your changes, "git svn fetch" will seemingly fetch much more including ridiculously long checkouts of new branches that you'll probably never look at, and "git svn dcommit" will commit your changes.

Everything is absurdly fast, as usual for git. Except for checking out updates from SVN. That's absurdly slow. As in "go get some coffee while you wait if you didn't rebase in the last few days". And if someone makes a new branch it takes approximately 1.47 eternities to check out with git svn fetch. I don't know why this is so slow, I asked in #git but they blamed it on SVN. Oh well. But you can use git.

Using the Mediawiki SVN Mirror on Gitorious
There's an existing Mediawiki SVN Mirror hosted on Gitorious. To get it do:

git clone git://gitorious.org/mediawiki-svn-mirror/mainline.git

Creating your own mirror
You can check out MediaWiki's SVN repository from scratch by doing:

mkdir mw-git cd mw-git git svn init \ --trunk trunk \ --branches branches \ --tags tags \ http://svn.wikimedia.org/svnroot/mediawiki

If you have commit access that command would be:

git svn init \ --trunk trunk \ --branches branches \ --tags tags \ svn+ssh://svn.wikimedia.org/svnroot/mediawiki

Then to fetch all the revisions do:

git svn fetch

This will give you the full history of trunk, branches, and tags to work on locally. However, the slight downside is it takes about three days to actually complete.

Working with Git
The following documentation all assumes you're working with a remote Git repository created as discussed above.

Checking out new branches
By default you only track the  branch which corresponds to Subversion's. To check out and track another branch do:

git checkout -b REL1_15 --track origin/REL1_15

Rebuilding SVN metadata
TODO: If I get someone else's Git conversion how do I get it into a form like I'd  it? See this for an example that doesn't work. It gives:

$ git update-ref refs/remotes/trunk origin/svn/trunk fatal: origin/svn/trunk: not a valid SHA1

Commit / dcommit
TODO: How to commit / dcommit?

Links

 * Git's website with documentation
 * An introduction to git-svn for Subversion/SVK users and deserter by Sam Vilain