Git-Bzr-NG or How I Learned to Stop Worrying and Love the Code

git-bzr-ng is a bidirectional bridge between git and bzr that lets you stop worrying which version control the code you love is using -- as long as they are using git or bzr ;) (hg coming soon?).

Easy to use and cleanly written (I hope (send patches!)). Check out the examples below for basic usage.

Example usage

Clone a launchpad repo

$ git bzr clone lp:nova nova

$ cd nova
$ git branch -a

# result ->
#   bzr/master
# * master

Make a new branch

$ git checkout -b touch_branch

$ echo "TOUCH" >> README
$ git commit -a -m "touch touch"
$ git bzr push lp:~termie/nova/touch_branch

Now you've got a cool new branch up on a server!
Go ahead and do some more work and push again.
It will go to the same place, and much faster now.

$ echo "TOUCH" >> README
$ git commit -a -m "touch touch"
$ git bzr push

How is trunk doing?
Sync is a slow operation the first time, like push.
They both speed up after they've done it once for a given branch.

$ git checkout master
$ git bzr sync
$ git diff bzr/master

Somebody else has a patch and you want to test it locally.

$ git bzr import lp:~vishvananda/nova/fix-part fix-part
$ git diff touch_branch

Like those changes? Pull them into your own branch and push them
$ git checkout touch_branch
$ git pull . -- fix-part
$ git bzr push

See test.sh for even more examples. Please try it out and report any issues to the github tracker at http://github.com/termie/git-bzr-ng/issues so we can sort them out quickly.

Extra Notes

I've tried to keep you from doing anything too weird, but since it is git I am sure you can figure out someway to mess stuff up, so if you somehow manage to push weird data to your bzr/* branches, you can always force an overwrite with:

$ git bzr sync --overwrite bzr/nova

It won't do anything to any branch except the one mentioned and on that one it effectively does a bzr pull --overwrite.

Requirements

• git (some recentish version)
• bzr 2.2 or bzr 2.3.0
• bzr-fastimport 0.10 http://launchpad.net/bzr-fastimport/trunk/0.10.0/+download/bzr-fastimport-0.10.0.tar.gz
• python-fastimport, for bzr-fastimport (bzr branch lp:python-fastimport)
• You also need to put the git-bzr script somewhere in your path

Troubleshooting

For other issues, please see: http://github.com/termie/git-bzr-ng/issues

don't use bzr 2.3b

If you see

AttributeError: 'BTreeBuilder' object has no attribute '_find_ancestors'

it means you have the bzr 2.3 beta installed, git-bzr-ng currently works unpatched with bzr 2.2 and bzr 2.3.0. It is possible to patch bzr 2.3b to correct the issue, but 2.3.0 is easy to install with pip.

tests run against multiple versions

If you are running the tests (python run_tests.py) keep in mind that one set of tests is actually running against bzr-fastimport's HEAD so it doesn't always work, so if you see failures check that they are in GitBzrTest or GitBzrStableTarballTest first.

when all else fails: git bzr clear

Additionally there is a command git bzr clear that will wipe out the bzr-related information for a given branch so if you have somehow found yourself in a bind, it should help you wipe the slate to try again.

Kind thanks to

• bzr-fastimport: https://launchpad.net/bzr-fastimport
• Evan Martin's git-cl: http://neugierig.org/software/git/?r=git-cl
• kfish's git-bzr: http://github.com/kfish/git-bzr