# 4. Getting the Source

## 4.1. Source package URLs

Bazaar provides some very nice shortcuts for accessing Launchpad’s source branches of packages in both Ubuntu and Debian.

To refer to source branches use:

    ubuntu:package

where package refers to the package name you’re interested in. This URL refers to the package in the current development version of Ubuntu. To refer to the branch of Tomboy in the development version, you would use:

    ubuntu:tomboy

To refer to the version of a source package in an older release of Ubuntu, just prefix the package name with the release’s code name. E.g. to refer to Tomboy’s source package in Saucy use:

    ubuntu:saucy/tomboy

Since they are unique, you can also abbreviate the distro-series name:

    ubuntu:s/tomboy

You can use a similar scheme to access the source branches in Debian, although there are no shortcuts for the Debian distro-series names. To access the Tomboy branch in the current development series for Debian use:

    debianlp:tomboy

and to access Tomboy in Debian Wheezy use:

    debianlp:wheezy/tomboy

## 4.2. Getting the source

Every source package in Ubuntu has an associated source branch on Launchpad. These source branches are updated automatically by Launchpad, although the process is not currently foolproof.

There are a couple of things that we do first in order to make the workflow more efficient later. Once you are used to the process you will learn when it makes sense to skip these steps.

### 4.2.1. Creating a shared repository

Say that you want to work on the Tomboy package, and you’ve verified that the source package is named `tomboy`. Before actually branching the code for Tomboy, create a shared repository to hold the branches for this package. The shared repository will make future work much more efficient.

Do this using the bzr init-repo command, passing it the directory name we would like to use:

    $ bzr init-repo tomboy

You will see that a tomboy directory is created in your current working area. Change to this new directory for the rest of your work:

    $ cd tomboy

### 4.2.2. Getting the trunk branch

We use the bzr branch command to create a local branch of the package. We’ll name the target directory tomboy.dev just to keep things easy to remember:

    $ bzr branch ubuntu:tomboy tomboy.dev

The tomboy.dev directory represents the version of Tomboy in the development version of Ubuntu, and you can always `cd` into this directory and do a bzr pull to get any future updates.

### 4.2.3. Ensuring the version is up to date

When you do your `bzr branch` you will get a message telling you if the packaging branch is up to date. For example:

    $ bzr branch ubuntu:tomboy
    Most recent Ubuntu version: 1.8.0-1ubuntu1.2
    Packaging branch status: CURRENT
    Branched 86 revisions.

Occasionally the importer fails and packaging branches do not match what is in the archive. A message saying:

    Packaging branch status: OUT-OF-DATE

means the importer has failed. You can find out why on http://package-import.ubuntu.com/status/ and file a bug on the UDD project to get the issue resolved.

### 4.2.4. Upstream Tar

You can get the upstream tar by running:

    bzr get-orig-source

This will try a number of methods to get the upstream tar, firstly by recreating it from the `upstream-x.y` tag in the bzr archive, then by downloading from the Ubuntu archive, lastly by running `debian/rules get-orig-source`. The upstream tar will also be recreated when using bzr to build the package:

    bzr builddeb

The builddeb plugin has several configuration options.

### 4.2.5. Getting a branch for a particular release

When you want to do something like a stable release update (SRU), or you just want to examine the code in an old release, you’ll want to grab the branch corresponding to a particular Ubuntu release. For example, to get the Tomboy package for Quantal do:

    $ bzr branch ubuntu:m/tomboy quantal

### 4.2.6. Importing a Debian source package

If the package you want to work on is available in Debian but not Ubuntu, it’s still easy to import the code to a local bzr branch for development. Let’s say you want to import the newpackage source package. We’ll start by creating a shared repository as normal, but we also have to create a working tree to which the source package will be imported (remember to cd out of the tomboy directory created above):

    $ bzr init-repo newpackage
    $ cd newpackage
    $ bzr init debian
    $ cd debian
    $ bzr import-dsc http://ftp.de.debian.org/debian/pool/main/n/newpackage/newpackage_1.0-1.dsc

As you can see, we just need to provide the remote location of the dsc file, and Bazaar will do the rest. You’ve now got a Bazaar source branch.